* Re: [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge
2022-01-31 8:55 [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge AngeloGioacchino Del Regno
@ 2022-02-08 8:20 ` CK Hu
2022-02-08 8:32 ` CK Hu
2022-02-09 14:48 ` Nícolas F. R. A. Prado
2022-02-09 15:06 ` Chun-Kuang Hu
2 siblings, 1 reply; 6+ messages in thread
From: CK Hu @ 2022-02-08 8:20 UTC (permalink / raw)
To: AngeloGioacchino Del Regno, dri-devel
Cc: chunkuang.hu, airlied, linux-kernel, stable, andrzej.hajda,
linux-mediatek, Jagan Teki, matthias.bgg, kernel,
linux-arm-kernel
Hi, Angelo:
On Mon, 2022-01-31 at 09:55 +0100, AngeloGioacchino Del Regno wrote:
> DRM bridge drivers are now attaching their DSI device at probe time,
> which requires us to register our DSI host in order to let the bridge
> to probe: this recently started producing an endless -EPROBE_DEFER
> loop on some machines that are using external bridges, like the
> parade-ps8640, found on the ACER Chromebook R13.
>
> Now that the DSI hosts/devices probe sequence is documented, we can
> do adjustments to the mtk_dsi driver as to both fix now and make sure
> to avoid this situation in the future: for this, following what is
> documented in drm_bridge.c, move the mtk_dsi component_add() to the
> mtk_dsi_ops.attach callback and delete it in the detach callback;
> keeping in mind that we are registering a drm_bridge for our DSI,
> which is only used/attached if the DSI Host is bound, it wouldn't
> make sense to keep adding our bridge at probe time (as it would
> be useless to have it if mtk_dsi_ops.attach() fails!), so also move
> that one to the dsi host attach function (and remove it in detach).
>
> Cc: <stable@vger.kernel.org> # 5.15.x
> Signed-off-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++----------
> ----
> 1 file changed, 84 insertions(+), 83 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 5d90d2eb0019..bced4c7d668e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev)
> mtk_dsi_poweroff(dsi);
> }
>
>
[snip]
> +
> static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
> struct mipi_dsi_device *device)
> {
> struct mtk_dsi *dsi = host_to_dsi(host);
> + struct device *dev = host->dev;
> + int ret;
>
> dsi->lanes = device->lanes;
> dsi->format = device->format;
> dsi->mode_flags = device->mode_flags;
> + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0,
> 0);
The original would process panel. Why do you remove the panel part?
It's better that someone has a platform of DSI->Panel to test this
patch.
Regards,
CK
> + if (IS_ERR(dsi->next_bridge))
> + return PTR_ERR(dsi->next_bridge);
> +
> + drm_bridge_add(&dsi->bridge);
> +
> + ret = component_add(host->dev, &mtk_dsi_component_ops);
> + if (ret) {
> + DRM_ERROR("failed to add dsi_host component: %d\n",
> ret);
> + drm_bridge_remove(&dsi->bridge);
> + return ret;
> + }
>
> return 0;
> }
>
> +static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
> + struct mipi_dsi_device *device)
> +{
> + struct mtk_dsi *dsi = host_to_dsi(host);
> +
> + component_del(host->dev, &mtk_dsi_component_ops);
> + drm_bridge_remove(&dsi->bridge);
> + return 0;
> +}
> +
> static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi)
> {
> int ret;
> @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct
> mipi_dsi_host *host,
>
> static const struct mipi_dsi_host_ops mtk_dsi_ops = {
> .attach = mtk_dsi_host_attach,
> + .detach = mtk_dsi_host_detach,
> .transfer = mtk_dsi_host_transfer,
> };
>
>
[snip]
> -
> static int mtk_dsi_probe(struct platform_device *pdev)
> {
> struct mtk_dsi *dsi;
> struct device *dev = &pdev->dev;
> - struct drm_panel *panel;
> struct resource *regs;
> int irq_num;
> int ret;
> @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct
> platform_device *pdev)
> return ret;
> }
>
> - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> - &panel, &dsi->next_bridge);
> - if (ret)
> - goto err_unregister_host;
> -
> - if (panel) {
> - dsi->next_bridge = devm_drm_panel_bridge_add(dev,
> panel);
> - if (IS_ERR(dsi->next_bridge)) {
> - ret = PTR_ERR(dsi->next_bridge);
> - goto err_unregister_host;
> - }
> - }
> -
> dsi->driver_data = of_device_get_match_data(dev);
>
> dsi->engine_clk = devm_clk_get(dev, "engine");
> @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct
> platform_device *pdev)
> dsi->bridge.of_node = dev->of_node;
> dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
>
> - drm_bridge_add(&dsi->bridge);
> -
> - ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
> - if (ret) {
> - dev_err(&pdev->dev, "failed to add component: %d\n",
> ret);
> - goto err_unregister_host;
> - }
> -
> return 0;
>
> err_unregister_host:
> @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct
> platform_device *pdev)
> struct mtk_dsi *dsi = platform_get_drvdata(pdev);
>
> mtk_output_dsi_disable(dsi);
> - drm_bridge_remove(&dsi->bridge);
> - component_del(&pdev->dev, &mtk_dsi_component_ops);
> mipi_dsi_host_unregister(&dsi->host);
>
> return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge
2022-02-08 8:20 ` CK Hu
@ 2022-02-08 8:32 ` CK Hu
2022-02-08 9:03 ` AngeloGioacchino Del Regno
0 siblings, 1 reply; 6+ messages in thread
From: CK Hu @ 2022-02-08 8:32 UTC (permalink / raw)
To: AngeloGioacchino Del Regno, dri-devel
Cc: chunkuang.hu, airlied, linux-kernel, stable, andrzej.hajda,
linux-mediatek, Jagan Teki, matthias.bgg, kernel,
linux-arm-kernel
Hi, Angelo:
On Tue, 2022-02-08 at 16:20 +0800, CK Hu wrote:
> Hi, Angelo:
>
> On Mon, 2022-01-31 at 09:55 +0100, AngeloGioacchino Del Regno wrote:
> > DRM bridge drivers are now attaching their DSI device at probe
> > time,
> > which requires us to register our DSI host in order to let the
> > bridge
> > to probe: this recently started producing an endless -EPROBE_DEFER
> > loop on some machines that are using external bridges, like the
> > parade-ps8640, found on the ACER Chromebook R13.
> >
> > Now that the DSI hosts/devices probe sequence is documented, we can
> > do adjustments to the mtk_dsi driver as to both fix now and make
> > sure
> > to avoid this situation in the future: for this, following what is
> > documented in drm_bridge.c, move the mtk_dsi component_add() to the
> > mtk_dsi_ops.attach callback and delete it in the detach callback;
> > keeping in mind that we are registering a drm_bridge for our DSI,
> > which is only used/attached if the DSI Host is bound, it wouldn't
> > make sense to keep adding our bridge at probe time (as it would
> > be useless to have it if mtk_dsi_ops.attach() fails!), so also move
> > that one to the dsi host attach function (and remove it in detach).
> >
> > Cc: <stable@vger.kernel.org> # 5.15.x
> > Signed-off-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno@collabora.com>
> > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
> > Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
> >
> > ---
> > drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++----------
> > ----
> > 1 file changed, 84 insertions(+), 83 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index 5d90d2eb0019..bced4c7d668e 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev)
> > mtk_dsi_poweroff(dsi);
> > }
> >
> >
>
> [snip]
>
> > +
> > static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
> > struct mipi_dsi_device *device)
> > {
> > struct mtk_dsi *dsi = host_to_dsi(host);
> > + struct device *dev = host->dev;
> > + int ret;
> >
> > dsi->lanes = device->lanes;
> > dsi->format = device->format;
> > dsi->mode_flags = device->mode_flags;
> > + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0,
> > 0);
>
> The original would process panel. Why do you remove the panel part?
> It's better that someone has a platform of DSI->Panel to test this
> patch.
Sorry, devm_drm_of_get_bridge() has processed the panel part, so for
this patch,
Reviewed-by: CK Hu <ck.hu@mediatek.com>
>
> Regards,
> CK
>
> > + if (IS_ERR(dsi->next_bridge))
> > + return PTR_ERR(dsi->next_bridge);
> > +
> > + drm_bridge_add(&dsi->bridge);
> > +
> > + ret = component_add(host->dev, &mtk_dsi_component_ops);
> > + if (ret) {
> > + DRM_ERROR("failed to add dsi_host component: %d\n",
> > ret);
> > + drm_bridge_remove(&dsi->bridge);
> > + return ret;
> > + }
> >
> > return 0;
> > }
> >
> > +static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
> > + struct mipi_dsi_device *device)
> > +{
> > + struct mtk_dsi *dsi = host_to_dsi(host);
> > +
> > + component_del(host->dev, &mtk_dsi_component_ops);
> > + drm_bridge_remove(&dsi->bridge);
> > + return 0;
> > +}
> > +
> > static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi)
> > {
> > int ret;
> > @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct
> > mipi_dsi_host *host,
> >
> > static const struct mipi_dsi_host_ops mtk_dsi_ops = {
> > .attach = mtk_dsi_host_attach,
> > + .detach = mtk_dsi_host_detach,
> > .transfer = mtk_dsi_host_transfer,
> > };
> >
> >
>
> [snip]
>
> > -
> > static int mtk_dsi_probe(struct platform_device *pdev)
> > {
> > struct mtk_dsi *dsi;
> > struct device *dev = &pdev->dev;
> > - struct drm_panel *panel;
> > struct resource *regs;
> > int irq_num;
> > int ret;
> > @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct
> > platform_device *pdev)
> > return ret;
> > }
> >
> > - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> > - &panel, &dsi->next_bridge);
> > - if (ret)
> > - goto err_unregister_host;
> > -
> > - if (panel) {
> > - dsi->next_bridge = devm_drm_panel_bridge_add(dev,
> > panel);
> > - if (IS_ERR(dsi->next_bridge)) {
> > - ret = PTR_ERR(dsi->next_bridge);
> > - goto err_unregister_host;
> > - }
> > - }
> > -
> > dsi->driver_data = of_device_get_match_data(dev);
> >
> > dsi->engine_clk = devm_clk_get(dev, "engine");
> > @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct
> > platform_device *pdev)
> > dsi->bridge.of_node = dev->of_node;
> > dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
> >
> > - drm_bridge_add(&dsi->bridge);
> > -
> > - ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
> > - if (ret) {
> > - dev_err(&pdev->dev, "failed to add component: %d\n",
> > ret);
> > - goto err_unregister_host;
> > - }
> > -
> > return 0;
> >
> > err_unregister_host:
> > @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct
> > platform_device *pdev)
> > struct mtk_dsi *dsi = platform_get_drvdata(pdev);
> >
> > mtk_output_dsi_disable(dsi);
> > - drm_bridge_remove(&dsi->bridge);
> > - component_del(&pdev->dev, &mtk_dsi_component_ops);
> > mipi_dsi_host_unregister(&dsi->host);
> >
> > return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge
2022-02-08 8:32 ` CK Hu
@ 2022-02-08 9:03 ` AngeloGioacchino Del Regno
0 siblings, 0 replies; 6+ messages in thread
From: AngeloGioacchino Del Regno @ 2022-02-08 9:03 UTC (permalink / raw)
To: CK Hu, dri-devel
Cc: chunkuang.hu, airlied, linux-kernel, stable, andrzej.hajda,
linux-mediatek, Jagan Teki, matthias.bgg, kernel,
linux-arm-kernel
Il 08/02/22 09:32, CK Hu ha scritto:
> Hi, Angelo:
>
> On Tue, 2022-02-08 at 16:20 +0800, CK Hu wrote:
>> Hi, Angelo:
>>
>> On Mon, 2022-01-31 at 09:55 +0100, AngeloGioacchino Del Regno wrote:
>>> DRM bridge drivers are now attaching their DSI device at probe
>>> time,
>>> which requires us to register our DSI host in order to let the
>>> bridge
>>> to probe: this recently started producing an endless -EPROBE_DEFER
>>> loop on some machines that are using external bridges, like the
>>> parade-ps8640, found on the ACER Chromebook R13.
>>>
>>> Now that the DSI hosts/devices probe sequence is documented, we can
>>> do adjustments to the mtk_dsi driver as to both fix now and make
>>> sure
>>> to avoid this situation in the future: for this, following what is
>>> documented in drm_bridge.c, move the mtk_dsi component_add() to the
>>> mtk_dsi_ops.attach callback and delete it in the detach callback;
>>> keeping in mind that we are registering a drm_bridge for our DSI,
>>> which is only used/attached if the DSI Host is bound, it wouldn't
>>> make sense to keep adding our bridge at probe time (as it would
>>> be useless to have it if mtk_dsi_ops.attach() fails!), so also move
>>> that one to the dsi host attach function (and remove it in detach).
>>>
>>> Cc: <stable@vger.kernel.org> # 5.15.x
>>> Signed-off-by: AngeloGioacchino Del Regno <
>>> angelogioacchino.delregno@collabora.com>
>>> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
>>> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
>>>
>>> ---
>>> drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++----------
>>> ----
>>> 1 file changed, 84 insertions(+), 83 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
>>> b/drivers/gpu/drm/mediatek/mtk_dsi.c
>>> index 5d90d2eb0019..bced4c7d668e 100644
>>> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
>>> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
>>> @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev)
>>> mtk_dsi_poweroff(dsi);
>>> }
>>>
>>>
>>
>> [snip]
>>
>>> +
>>> static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
>>> struct mipi_dsi_device *device)
>>> {
>>> struct mtk_dsi *dsi = host_to_dsi(host);
>>> + struct device *dev = host->dev;
>>> + int ret;
>>>
>>> dsi->lanes = device->lanes;
>>> dsi->format = device->format;
>>> dsi->mode_flags = device->mode_flags;
>>> + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0,
>>> 0);
>>
>> The original would process panel. Why do you remove the panel part?
>> It's better that someone has a platform of DSI->Panel to test this
>> patch.
>
> Sorry, devm_drm_of_get_bridge() has processed the panel part, so for
> this patch,
>
> Reviewed-by: CK Hu <ck.hu@mediatek.com>
>
No worries! Thanks for the review/approval.
Regards,
Angelo
>>
>> Regards,
>> CK
>>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge
2022-01-31 8:55 [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge AngeloGioacchino Del Regno
2022-02-08 8:20 ` CK Hu
@ 2022-02-09 14:48 ` Nícolas F. R. A. Prado
2022-02-09 15:06 ` Chun-Kuang Hu
2 siblings, 0 replies; 6+ messages in thread
From: Nícolas F. R. A. Prado @ 2022-02-09 14:48 UTC (permalink / raw)
To: AngeloGioacchino Del Regno
Cc: dri-devel, linux-mediatek, linux-arm-kernel, linux-kernel,
chunkuang.hu, p.zabel, airlied, daniel, matthias.bgg, kernel,
andrzej.hajda, stable, Jagan Teki
Hi Angelo,
On Mon, Jan 31, 2022 at 09:55:20AM +0100, AngeloGioacchino Del Regno wrote:
> DRM bridge drivers are now attaching their DSI device at probe time,
> which requires us to register our DSI host in order to let the bridge
> to probe: this recently started producing an endless -EPROBE_DEFER
> loop on some machines that are using external bridges, like the
> parade-ps8640, found on the ACER Chromebook R13.
>
> Now that the DSI hosts/devices probe sequence is documented, we can
> do adjustments to the mtk_dsi driver as to both fix now and make sure
> to avoid this situation in the future: for this, following what is
> documented in drm_bridge.c, move the mtk_dsi component_add() to the
> mtk_dsi_ops.attach callback and delete it in the detach callback;
> keeping in mind that we are registering a drm_bridge for our DSI,
> which is only used/attached if the DSI Host is bound, it wouldn't
> make sense to keep adding our bridge at probe time (as it would
> be useless to have it if mtk_dsi_ops.attach() fails!), so also move
> that one to the dsi host attach function (and remove it in detach).
>
> Cc: <stable@vger.kernel.org> # 5.15.x
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Thanks,
Nícolas
>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++--------------
> 1 file changed, 84 insertions(+), 83 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 5d90d2eb0019..bced4c7d668e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev)
> mtk_dsi_poweroff(dsi);
> }
>
> +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> +{
> + int ret;
> +
> + ret = drm_simple_encoder_init(drm, &dsi->encoder,
> + DRM_MODE_ENCODER_DSI);
> + if (ret) {
> + DRM_ERROR("Failed to encoder init to drm\n");
> + return ret;
> + }
> +
> + dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);
> +
> + ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> + if (ret)
> + goto err_cleanup_encoder;
> +
> + dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
> + if (IS_ERR(dsi->connector)) {
> + DRM_ERROR("Unable to create bridge connector\n");
> + ret = PTR_ERR(dsi->connector);
> + goto err_cleanup_encoder;
> + }
> + drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> +
> + return 0;
> +
> +err_cleanup_encoder:
> + drm_encoder_cleanup(&dsi->encoder);
> + return ret;
> +}
> +
> +static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> +{
> + int ret;
> + struct drm_device *drm = data;
> + struct mtk_dsi *dsi = dev_get_drvdata(dev);
> +
> + ret = mtk_dsi_encoder_init(drm, dsi);
> + if (ret)
> + return ret;
> +
> + return device_reset_optional(dev);
> +}
> +
> +static void mtk_dsi_unbind(struct device *dev, struct device *master,
> + void *data)
> +{
> + struct mtk_dsi *dsi = dev_get_drvdata(dev);
> +
> + drm_encoder_cleanup(&dsi->encoder);
> +}
> +
> +static const struct component_ops mtk_dsi_component_ops = {
> + .bind = mtk_dsi_bind,
> + .unbind = mtk_dsi_unbind,
> +};
> +
> static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
> struct mipi_dsi_device *device)
> {
> struct mtk_dsi *dsi = host_to_dsi(host);
> + struct device *dev = host->dev;
> + int ret;
>
> dsi->lanes = device->lanes;
> dsi->format = device->format;
> dsi->mode_flags = device->mode_flags;
> + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
> + if (IS_ERR(dsi->next_bridge))
> + return PTR_ERR(dsi->next_bridge);
> +
> + drm_bridge_add(&dsi->bridge);
> +
> + ret = component_add(host->dev, &mtk_dsi_component_ops);
> + if (ret) {
> + DRM_ERROR("failed to add dsi_host component: %d\n", ret);
> + drm_bridge_remove(&dsi->bridge);
> + return ret;
> + }
>
> return 0;
> }
>
> +static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
> + struct mipi_dsi_device *device)
> +{
> + struct mtk_dsi *dsi = host_to_dsi(host);
> +
> + component_del(host->dev, &mtk_dsi_component_ops);
> + drm_bridge_remove(&dsi->bridge);
> + return 0;
> +}
> +
> static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi)
> {
> int ret;
> @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
>
> static const struct mipi_dsi_host_ops mtk_dsi_ops = {
> .attach = mtk_dsi_host_attach,
> + .detach = mtk_dsi_host_detach,
> .transfer = mtk_dsi_host_transfer,
> };
>
> -static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> -{
> - int ret;
> -
> - ret = drm_simple_encoder_init(drm, &dsi->encoder,
> - DRM_MODE_ENCODER_DSI);
> - if (ret) {
> - DRM_ERROR("Failed to encoder init to drm\n");
> - return ret;
> - }
> -
> - dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);
> -
> - ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> - DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> - if (ret)
> - goto err_cleanup_encoder;
> -
> - dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
> - if (IS_ERR(dsi->connector)) {
> - DRM_ERROR("Unable to create bridge connector\n");
> - ret = PTR_ERR(dsi->connector);
> - goto err_cleanup_encoder;
> - }
> - drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> -
> - return 0;
> -
> -err_cleanup_encoder:
> - drm_encoder_cleanup(&dsi->encoder);
> - return ret;
> -}
> -
> -static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> -{
> - int ret;
> - struct drm_device *drm = data;
> - struct mtk_dsi *dsi = dev_get_drvdata(dev);
> -
> - ret = mtk_dsi_encoder_init(drm, dsi);
> - if (ret)
> - return ret;
> -
> - return device_reset_optional(dev);
> -}
> -
> -static void mtk_dsi_unbind(struct device *dev, struct device *master,
> - void *data)
> -{
> - struct mtk_dsi *dsi = dev_get_drvdata(dev);
> -
> - drm_encoder_cleanup(&dsi->encoder);
> -}
> -
> -static const struct component_ops mtk_dsi_component_ops = {
> - .bind = mtk_dsi_bind,
> - .unbind = mtk_dsi_unbind,
> -};
> -
> static int mtk_dsi_probe(struct platform_device *pdev)
> {
> struct mtk_dsi *dsi;
> struct device *dev = &pdev->dev;
> - struct drm_panel *panel;
> struct resource *regs;
> int irq_num;
> int ret;
> @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> return ret;
> }
>
> - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> - &panel, &dsi->next_bridge);
> - if (ret)
> - goto err_unregister_host;
> -
> - if (panel) {
> - dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);
> - if (IS_ERR(dsi->next_bridge)) {
> - ret = PTR_ERR(dsi->next_bridge);
> - goto err_unregister_host;
> - }
> - }
> -
> dsi->driver_data = of_device_get_match_data(dev);
>
> dsi->engine_clk = devm_clk_get(dev, "engine");
> @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> dsi->bridge.of_node = dev->of_node;
> dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
>
> - drm_bridge_add(&dsi->bridge);
> -
> - ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
> - if (ret) {
> - dev_err(&pdev->dev, "failed to add component: %d\n", ret);
> - goto err_unregister_host;
> - }
> -
> return 0;
>
> err_unregister_host:
> @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct platform_device *pdev)
> struct mtk_dsi *dsi = platform_get_drvdata(pdev);
>
> mtk_output_dsi_disable(dsi);
> - drm_bridge_remove(&dsi->bridge);
> - component_del(&pdev->dev, &mtk_dsi_component_ops);
> mipi_dsi_host_unregister(&dsi->host);
>
> return 0;
> --
> 2.33.1
>
>
> --
> To unsubscribe, send mail to kernel-unsubscribe@lists.collabora.co.uk.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge
2022-01-31 8:55 [PATCH v4] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge AngeloGioacchino Del Regno
2022-02-08 8:20 ` CK Hu
2022-02-09 14:48 ` Nícolas F. R. A. Prado
@ 2022-02-09 15:06 ` Chun-Kuang Hu
2 siblings, 0 replies; 6+ messages in thread
From: Chun-Kuang Hu @ 2022-02-09 15:06 UTC (permalink / raw)
To: AngeloGioacchino Del Regno
Cc: DRI Development, Chun-Kuang Hu, David Airlie, linux-kernel,
stable, andrzej.hajda, moderated list:ARM/Mediatek SoC support,
Jagan Teki, Matthias Brugger, Collabora Kernel ML, Linux ARM
Hi, Angelo:
AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> 於
2022年1月31日 週一 下午4:55寫道：
>
> DRM bridge drivers are now attaching their DSI device at probe time,
> which requires us to register our DSI host in order to let the bridge
> to probe: this recently started producing an endless -EPROBE_DEFER
> loop on some machines that are using external bridges, like the
> parade-ps8640, found on the ACER Chromebook R13.
>
> Now that the DSI hosts/devices probe sequence is documented, we can
> do adjustments to the mtk_dsi driver as to both fix now and make sure
> to avoid this situation in the future: for this, following what is
> documented in drm_bridge.c, move the mtk_dsi component_add() to the
> mtk_dsi_ops.attach callback and delete it in the detach callback;
> keeping in mind that we are registering a drm_bridge for our DSI,
> which is only used/attached if the DSI Host is bound, it wouldn't
> make sense to keep adding our bridge at probe time (as it would
> be useless to have it if mtk_dsi_ops.attach() fails!), so also move
> that one to the dsi host attach function (and remove it in detach).
Applied to mediatek-drm-fixes[1], thanks.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes
Regards,
Chun-Kuang.
>
> Cc: <stable@vger.kernel.org> # 5.15.x
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++--------------
> 1 file changed, 84 insertions(+), 83 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 5d90d2eb0019..bced4c7d668e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev)
> mtk_dsi_poweroff(dsi);
> }
>
> +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> +{
> + int ret;
> +
> + ret = drm_simple_encoder_init(drm, &dsi->encoder,
> + DRM_MODE_ENCODER_DSI);
> + if (ret) {
> + DRM_ERROR("Failed to encoder init to drm\n");
> + return ret;
> + }
> +
> + dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);
> +
> + ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> + if (ret)
> + goto err_cleanup_encoder;
> +
> + dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
> + if (IS_ERR(dsi->connector)) {
> + DRM_ERROR("Unable to create bridge connector\n");
> + ret = PTR_ERR(dsi->connector);
> + goto err_cleanup_encoder;
> + }
> + drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> +
> + return 0;
> +
> +err_cleanup_encoder:
> + drm_encoder_cleanup(&dsi->encoder);
> + return ret;
> +}
> +
> +static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> +{
> + int ret;
> + struct drm_device *drm = data;
> + struct mtk_dsi *dsi = dev_get_drvdata(dev);
> +
> + ret = mtk_dsi_encoder_init(drm, dsi);
> + if (ret)
> + return ret;
> +
> + return device_reset_optional(dev);
> +}
> +
> +static void mtk_dsi_unbind(struct device *dev, struct device *master,
> + void *data)
> +{
> + struct mtk_dsi *dsi = dev_get_drvdata(dev);
> +
> + drm_encoder_cleanup(&dsi->encoder);
> +}
> +
> +static const struct component_ops mtk_dsi_component_ops = {
> + .bind = mtk_dsi_bind,
> + .unbind = mtk_dsi_unbind,
> +};
> +
> static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
> struct mipi_dsi_device *device)
> {
> struct mtk_dsi *dsi = host_to_dsi(host);
> + struct device *dev = host->dev;
> + int ret;
>
> dsi->lanes = device->lanes;
> dsi->format = device->format;
> dsi->mode_flags = device->mode_flags;
> + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
> + if (IS_ERR(dsi->next_bridge))
> + return PTR_ERR(dsi->next_bridge);
> +
> + drm_bridge_add(&dsi->bridge);
> +
> + ret = component_add(host->dev, &mtk_dsi_component_ops);
> + if (ret) {
> + DRM_ERROR("failed to add dsi_host component: %d\n", ret);
> + drm_bridge_remove(&dsi->bridge);
> + return ret;
> + }
>
> return 0;
> }
>
> +static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
> + struct mipi_dsi_device *device)
> +{
> + struct mtk_dsi *dsi = host_to_dsi(host);
> +
> + component_del(host->dev, &mtk_dsi_component_ops);
> + drm_bridge_remove(&dsi->bridge);
> + return 0;
> +}
> +
> static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi)
> {
> int ret;
> @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
>
> static const struct mipi_dsi_host_ops mtk_dsi_ops = {
> .attach = mtk_dsi_host_attach,
> + .detach = mtk_dsi_host_detach,
> .transfer = mtk_dsi_host_transfer,
> };
>
> -static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> -{
> - int ret;
> -
> - ret = drm_simple_encoder_init(drm, &dsi->encoder,
> - DRM_MODE_ENCODER_DSI);
> - if (ret) {
> - DRM_ERROR("Failed to encoder init to drm\n");
> - return ret;
> - }
> -
> - dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);
> -
> - ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> - DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> - if (ret)
> - goto err_cleanup_encoder;
> -
> - dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
> - if (IS_ERR(dsi->connector)) {
> - DRM_ERROR("Unable to create bridge connector\n");
> - ret = PTR_ERR(dsi->connector);
> - goto err_cleanup_encoder;
> - }
> - drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> -
> - return 0;
> -
> -err_cleanup_encoder:
> - drm_encoder_cleanup(&dsi->encoder);
> - return ret;
> -}
> -
> -static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> -{
> - int ret;
> - struct drm_device *drm = data;
> - struct mtk_dsi *dsi = dev_get_drvdata(dev);
> -
> - ret = mtk_dsi_encoder_init(drm, dsi);
> - if (ret)
> - return ret;
> -
> - return device_reset_optional(dev);
> -}
> -
> -static void mtk_dsi_unbind(struct device *dev, struct device *master,
> - void *data)
> -{
> - struct mtk_dsi *dsi = dev_get_drvdata(dev);
> -
> - drm_encoder_cleanup(&dsi->encoder);
> -}
> -
> -static const struct component_ops mtk_dsi_component_ops = {
> - .bind = mtk_dsi_bind,
> - .unbind = mtk_dsi_unbind,
> -};
> -
> static int mtk_dsi_probe(struct platform_device *pdev)
> {
> struct mtk_dsi *dsi;
> struct device *dev = &pdev->dev;
> - struct drm_panel *panel;
> struct resource *regs;
> int irq_num;
> int ret;
> @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> return ret;
> }
>
> - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> - &panel, &dsi->next_bridge);
> - if (ret)
> - goto err_unregister_host;
> -
> - if (panel) {
> - dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);
> - if (IS_ERR(dsi->next_bridge)) {
> - ret = PTR_ERR(dsi->next_bridge);
> - goto err_unregister_host;
> - }
> - }
> -
> dsi->driver_data = of_device_get_match_data(dev);
>
> dsi->engine_clk = devm_clk_get(dev, "engine");
> @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> dsi->bridge.of_node = dev->of_node;
> dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
>
> - drm_bridge_add(&dsi->bridge);
> -
> - ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
> - if (ret) {
> - dev_err(&pdev->dev, "failed to add component: %d\n", ret);
> - goto err_unregister_host;
> - }
> -
> return 0;
>
> err_unregister_host:
> @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct platform_device *pdev)
> struct mtk_dsi *dsi = platform_get_drvdata(pdev);
>
> mtk_output_dsi_disable(dsi);
> - drm_bridge_remove(&dsi->bridge);
> - component_del(&pdev->dev, &mtk_dsi_component_ops);
> mipi_dsi_host_unregister(&dsi->host);
>
> return 0;
> --
> 2.33.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread