[PATCH 0/2] extend "multi" functions and use them in sony-td4353-jdi

[PATCH 0/2] extend "multi" functions and use them in sony-td4353-jdi

[Tejas Vipin]

This patch removes mipi_dsi_dcs_set_tear_off and replaces it with a
multi version as after replacing it in sony-td4353-jdi, it doesn't
appear anywhere else. sony-td4353-jdi is converted to use multi style
functions, including mipi_dsi_dcs_set_tear_off_multi.

Tejas Vipin (2):
  drm/mipi-dsi: Replace mipi_dsi_dcs_set_tear_off with its multi version
  drm/panel: sony-td4353-jdi: transition to mipi_dsi wrapped functions

 drivers/gpu/drm/drm_mipi_dsi.c                |  42 +++----
 drivers/gpu/drm/panel/panel-sony-td4353-jdi.c | 107 ++++--------------
 include/drm/drm_mipi_dsi.h                    |   2 +-
 3 files changed, 47 insertions(+), 104 deletions(-)

-- 
2.48.1

[PATCH 1/2] drm/mipi-dsi: Replace mipi_dsi_dcs_set_tear_off with its multi version

[Tejas Vipin]

mipi_dsi_dcs_set_tear_off can heavily benefit from being converted
to a multi style function as it is often called in the context of
similar functions.

Signed-off-by: Tejas Vipin <tejasvipin76@gmail.com>
---
 drivers/gpu/drm/drm_mipi_dsi.c | 42 +++++++++++++++++++---------------
 include/drm/drm_mipi_dsi.h     |  2 +-
 2 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 5e5c5f84daac..2e148753ea97 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -1265,25 +1265,6 @@ int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,
 }
 EXPORT_SYMBOL(mipi_dsi_dcs_set_page_address);
 
-/**
- * mipi_dsi_dcs_set_tear_off() - turn off the display module's Tearing Effect
- *    output signal on the TE signal line
- * @dsi: DSI peripheral device
- *
- * Return: 0 on success or a negative error code on failure
- */
-int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi)
-{
-	ssize_t err;
-
-	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_OFF, NULL, 0);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_off);
-
 /**
  * mipi_dsi_dcs_set_tear_on() - turn on the display module's Tearing Effect
  *    output signal on the TE signal line.
@@ -1713,6 +1694,29 @@ void mipi_dsi_turn_on_peripheral_multi(struct mipi_dsi_multi_context *ctx)
 }
 EXPORT_SYMBOL(mipi_dsi_turn_on_peripheral_multi);
 
+/**
+ * mipi_dsi_dcs_set_tear_off_multi() - turn off the display module's Tearing Effect
+ *    output signal on the TE signal line
+ * @ctx: Context for multiple DSI transactions
+ */
+void mipi_dsi_dcs_set_tear_off_multi(struct mipi_dsi_multi_context *ctx)
+{
+	struct mipi_dsi_device *dsi = ctx->dsi;
+	struct device *dev = &dsi->dev;
+	ssize_t err;
+
+	if (ctx->accum_err)
+		return;
+
+	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_OFF, NULL, 0);
+	if (err < 0) {
+		ctx->accum_err = err;
+		dev_err(dev, "Failed to set tear off: %d\n",
+			ctx->accum_err);
+	}
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_off_multi);
+
 /**
  * mipi_dsi_dcs_soft_reset_multi() - perform a software reset of the display module
  * @ctx: Context for multiple DSI transactions
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 94400a78031f..bd40a443385c 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -346,7 +346,6 @@ int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start,
 				    u16 end);
 int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,
 				  u16 end);
-int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi);
 int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
 			     enum mipi_dsi_dcs_tear_mode mode);
 int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format);
@@ -379,6 +378,7 @@ void mipi_dsi_dcs_set_page_address_multi(struct mipi_dsi_multi_context *ctx,
 					 u16 start, u16 end);
 void mipi_dsi_dcs_set_tear_scanline_multi(struct mipi_dsi_multi_context *ctx,
 					  u16 scanline);
+void mipi_dsi_dcs_set_tear_off_multi(struct mipi_dsi_multi_context *ctx);
 
 /**
  * mipi_dsi_generic_write_seq - transmit data using a generic write packet
-- 
2.48.1

Re: [PATCH 1/2] drm/mipi-dsi: Replace mipi_dsi_dcs_set_tear_off with its multi version

[Doug Anderson]

Hi,

On Fri, Feb 14, 2025 at 9:30 AM Tejas Vipin <tejasvipin76@gmail.com> wrote:
>
> mipi_dsi_dcs_set_tear_off can heavily benefit from being converted
> to a multi style function as it is often called in the context of
> similar functions.

Given that it has one caller, the wording "heavily benefit" and "often
called" is a bit of a stretch.


> --- a/include/drm/drm_mipi_dsi.h
> +++ b/include/drm/drm_mipi_dsi.h
> @@ -346,7 +346,6 @@ int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start,
>                                     u16 end);
>  int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,
>                                   u16 end);
> -int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi);
>  int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
>                              enum mipi_dsi_dcs_tear_mode mode);
>  int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format);
> @@ -379,6 +378,7 @@ void mipi_dsi_dcs_set_page_address_multi(struct mipi_dsi_multi_context *ctx,
>                                          u16 start, u16 end);
>  void mipi_dsi_dcs_set_tear_scanline_multi(struct mipi_dsi_multi_context *ctx,
>                                           u16 scanline);
> +void mipi_dsi_dcs_set_tear_off_multi(struct mipi_dsi_multi_context *ctx);

This patch can't land as-is since it breaks bisection. In other words,
if someone has the first patch but not the second then it won't
compile because there will still be a user of
mipi_dsi_dcs_set_tear_off() but you've removed it. If they have the
second patch but not the first then it won't compile because
mipi_dsi_dcs_set_tear_off_multi() hasn't been introduced yet. You have
two options:

1. Turn your 2 patches into 3 patches. The first patch would need to
still provide the old function, the second patch would stay as-is, and
the third patch would remove the wrapper.

2. Just squash the two patches together.


If I were picking, I'd pick #2. While it's nice to separate out
patches, this is not a very complex case and adding code just to
delete it two patches later is a bit silly. That being said, it's a
tradeoff so if someone else has strong opinions I wouldn't object to
taking path #1.


-Doug

[PATCH 2/2] drm/panel: sony-td4353-jdi: transition to mipi_dsi wrapped functions

[Tejas Vipin]

Change the sony-td4353-jdi panel to use multi style functions for 
improved error handling.

Signed-off-by: Tejas Vipin <tejasvipin76@gmail.com>
---
 drivers/gpu/drm/panel/panel-sony-td4353-jdi.c | 107 ++++--------------
 1 file changed, 23 insertions(+), 84 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-sony-td4353-jdi.c b/drivers/gpu/drm/panel/panel-sony-td4353-jdi.c
index 472195d4bbbe..97f4bb4e1029 100644
--- a/drivers/gpu/drm/panel/panel-sony-td4353-jdi.c
+++ b/drivers/gpu/drm/panel/panel-sony-td4353-jdi.c
@@ -47,93 +47,40 @@ static inline struct sony_td4353_jdi *to_sony_td4353_jdi(struct drm_panel *panel
 static int sony_td4353_jdi_on(struct sony_td4353_jdi *ctx)
 {
 	struct mipi_dsi_device *dsi = ctx->dsi;
-	struct device *dev = &dsi->dev;
-	int ret;
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
 
 	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
 
-	ret = mipi_dsi_dcs_set_column_address(dsi, 0x0000, 1080 - 1);
-	if (ret < 0) {
-		dev_err(dev, "Failed to set column address: %d\n", ret);
-		return ret;
-	}
-
-	ret = mipi_dsi_dcs_set_page_address(dsi, 0x0000, 2160 - 1);
-	if (ret < 0) {
-		dev_err(dev, "Failed to set page address: %d\n", ret);
-		return ret;
-	}
-
-	ret = mipi_dsi_dcs_set_tear_scanline(dsi, 0);
-	if (ret < 0) {
-		dev_err(dev, "Failed to set tear scanline: %d\n", ret);
-		return ret;
-	}
-
-	ret = mipi_dsi_dcs_set_tear_on(dsi, MIPI_DSI_DCS_TEAR_MODE_VBLANK);
-	if (ret < 0) {
-		dev_err(dev, "Failed to set tear on: %d\n", ret);
-		return ret;
-	}
+	mipi_dsi_dcs_set_column_address_multi(&dsi_ctx, 0x0000, 1080 - 1);
+	mipi_dsi_dcs_set_page_address_multi(&dsi_ctx, 0x0000, 2160 - 1);
+	mipi_dsi_dcs_set_tear_scanline_multi(&dsi_ctx, 0);
+	mipi_dsi_dcs_set_tear_on_multi(&dsi_ctx, MIPI_DSI_DCS_TEAR_MODE_VBLANK);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_SET_ADDRESS_MODE, 0x00);
 
-	mipi_dsi_dcs_write_seq(dsi, MIPI_DCS_SET_ADDRESS_MODE, 0x00);
-
-	ret = mipi_dsi_dcs_set_pixel_format(dsi, 0x77);
-	if (ret < 0) {
-		dev_err(dev, "Failed to set pixel format: %d\n", ret);
-		return ret;
-	}
-
-	mipi_dsi_dcs_write_seq(dsi, MIPI_DCS_SET_PARTIAL_ROWS,
-			  0x00, 0x00, 0x08, 0x6f);
-
-	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
-	if (ret < 0) {
-		dev_err(dev, "Failed to exit sleep mode: %d\n", ret);
-		return ret;
-	}
-	msleep(70);
+	mipi_dsi_dcs_set_pixel_format_multi(&dsi_ctx, 0x77);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_SET_PARTIAL_ROWS,
+				     0x00, 0x00, 0x08, 0x6f);
 
-	mipi_dsi_dcs_write_seq(dsi, MIPI_DCS_WRITE_MEMORY_START);
+	mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 70);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_WRITE_MEMORY_START);
+	mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
 
-	ret = mipi_dsi_dcs_set_display_on(dsi);
-	if (ret < 0) {
-		dev_err(dev, "Failed to turn display on: %d\n", ret);
-		return ret;
-	}
-
-	return 0;
+	return dsi_ctx.accum_err;
 }
 
-static int sony_td4353_jdi_off(struct sony_td4353_jdi *ctx)
+static void sony_td4353_jdi_off(struct sony_td4353_jdi *ctx)
 {
 	struct mipi_dsi_device *dsi = ctx->dsi;
-	struct device *dev = &dsi->dev;
-	int ret;
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
 
 	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
 
-	ret = mipi_dsi_dcs_set_display_off(dsi);
-	if (ret < 0) {
-		dev_err(dev, "Failed to set display off: %d\n", ret);
-		return ret;
-	}
-	msleep(22);
-
-	ret = mipi_dsi_dcs_set_tear_off(dsi);
-	if (ret < 0) {
-		dev_err(dev, "Failed to set tear off: %d\n", ret);
-		return ret;
-	}
-
-	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
-	if (ret < 0) {
-		dev_err(dev, "Failed to enter sleep mode: %d\n", ret);
-		return ret;
-	}
-	msleep(80);
-
-	return 0;
+	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 22);
+	mipi_dsi_dcs_set_tear_off_multi(&dsi_ctx);
+	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 80);
 }
 
 static void sony_td4353_assert_reset_gpios(struct sony_td4353_jdi *ctx, int mode)
@@ -146,14 +93,11 @@ static void sony_td4353_assert_reset_gpios(struct sony_td4353_jdi *ctx, int mode
 static int sony_td4353_jdi_prepare(struct drm_panel *panel)
 {
 	struct sony_td4353_jdi *ctx = to_sony_td4353_jdi(panel);
-	struct device *dev = &ctx->dsi->dev;
 	int ret;
 
 	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
-	if (ret < 0) {
-		dev_err(dev, "Failed to enable regulators: %d\n", ret);
+	if (ret < 0)
 		return ret;
-	}
 
 	msleep(100);
 
@@ -161,7 +105,6 @@ static int sony_td4353_jdi_prepare(struct drm_panel *panel)
 
 	ret = sony_td4353_jdi_on(ctx);
 	if (ret < 0) {
-		dev_err(dev, "Failed to power on panel: %d\n", ret);
 		sony_td4353_assert_reset_gpios(ctx, 0);
 		regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
 		return ret;
@@ -173,12 +116,8 @@ static int sony_td4353_jdi_prepare(struct drm_panel *panel)
 static int sony_td4353_jdi_unprepare(struct drm_panel *panel)
 {
 	struct sony_td4353_jdi *ctx = to_sony_td4353_jdi(panel);
-	struct device *dev = &ctx->dsi->dev;
-	int ret;
 
-	ret = sony_td4353_jdi_off(ctx);
-	if (ret < 0)
-		dev_err(dev, "Failed to power off panel: %d\n", ret);
+	sony_td4353_jdi_off(ctx);
 
 	sony_td4353_assert_reset_gpios(ctx, 0);
 	regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
-- 
2.48.1

Re: [PATCH 2/2] drm/panel: sony-td4353-jdi: transition to mipi_dsi wrapped functions

[Doug Anderson]

Hi,

On Fri, Feb 14, 2025 at 9:30 AM Tejas Vipin <tejasvipin76@gmail.com> wrote:
>
> Change the sony-td4353-jdi panel to use multi style functions for
> improved error handling.
>
> Signed-off-by: Tejas Vipin <tejasvipin76@gmail.com>
> ---
>  drivers/gpu/drm/panel/panel-sony-td4353-jdi.c | 107 ++++--------------
>  1 file changed, 23 insertions(+), 84 deletions(-)

Nice diffstat and so much boilerplate error code removed. :-)

Reviewed-by: Douglas Anderson <dianders@chromium.org>

Note that I'm on vacation next week and it might take me a while to
dig out of email when I get back. More than happy if someone else
wants to land if the bisectability problems I talk about in patch #1
are resolved. Otherwise I'll get back to this eventually.


-Doug

Re: [PATCH 2/2] drm/panel: sony-td4353-jdi: transition to mipi_dsi wrapped functions

[Tejas Vipin]

On 2/15/25 6:12 AM, Doug Anderson wrote:
> Hi,
> 
> On Fri, Feb 14, 2025 at 9:30 AM Tejas Vipin <tejasvipin76@gmail.com> wrote:
>>
>> Change the sony-td4353-jdi panel to use multi style functions for
>> improved error handling.
>>
>> Signed-off-by: Tejas Vipin <tejasvipin76@gmail.com>
>> ---
>>  drivers/gpu/drm/panel/panel-sony-td4353-jdi.c | 107 ++++--------------
>>  1 file changed, 23 insertions(+), 84 deletions(-)
> 
> Nice diffstat and so much boilerplate error code removed. :-)
> 
> Reviewed-by: Douglas Anderson <dianders@chromium.org>

If I rebase both the patches into 1, should I still add the Reviewed-by
tag?

> 
> Note that I'm on vacation next week and it might take me a while to
> dig out of email when I get back. More than happy if someone else
> wants to land if the bisectability problems I talk about in patch #1
> are resolved. Otherwise I'll get back to this eventually.
> 
> 
> -Doug

-- 
Tejas Vipin

Re: [PATCH 2/2] drm/panel: sony-td4353-jdi: transition to mipi_dsi wrapped functions

[Doug Anderson]

Hi,

On Fri, Feb 14, 2025 at 8:46 PM Tejas Vipin <tejasvipin76@gmail.com> wrote:
>
>
>
> On 2/15/25 6:12 AM, Doug Anderson wrote:
> > Hi,
> >
> > On Fri, Feb 14, 2025 at 9:30 AM Tejas Vipin <tejasvipin76@gmail.com> wrote:
> >>
> >> Change the sony-td4353-jdi panel to use multi style functions for
> >> improved error handling.
> >>
> >> Signed-off-by: Tejas Vipin <tejasvipin76@gmail.com>
> >> ---
> >>  drivers/gpu/drm/panel/panel-sony-td4353-jdi.c | 107 ++++--------------
> >>  1 file changed, 23 insertions(+), 84 deletions(-)
> >
> > Nice diffstat and so much boilerplate error code removed. :-)
> >
> > Reviewed-by: Douglas Anderson <dianders@chromium.org>
>
> If I rebase both the patches into 1, should I still add the Reviewed-by
> tag?

Sorry, I was away, but it looks like you've sent v2 anyway and what
you did there is fine. In this case my "Reviewed-by" for the second
patch was more me helping myself keep track of the fact that I'd
already looked at all the contents on this patch and I was happy with
it.

For the record, most of the time it seems like you're expected to just
"guess" a bit what a reviewer would want. The absolute safest thing
you can do is to remove the "Reviewed-by" (like you did) but then also
"after the cut" in your new patch (like where you put version history)
indicate why you didn't carry the Reviewed-by. Like you could say:

NOTE: removed Doug's review tag in v2 because it was only provided for
one of the two patches that were squashed together.

Then if I wondered why you didn't carry my tag I'd have my answer.
Some reviewers get upset if you don't carry their tag forward and you
don't explain why you didn't. ;-)

-Doug