[PATCH v2 1/2] drm/bridge: anx7625: Propagate errors from sp_tx_rst_aux()

[PATCH v2 1/2] drm/bridge: anx7625: Propagate errors from sp_tx_rst_aux()

[Robert Foss]

The return value of sp_tx_rst_aux() is not propagated, which means
both compiler warnings and potential errors not being handled.

Fixes: 8bdfc5dae4e3 ("drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP")

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
---

Changes since v1:
 - Instead of discarding the error, propagate it until it
   is handled properly

 drivers/gpu/drm/bridge/analogix/anx7625.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 14d73fb1dd15b..ea414cd349b5c 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -720,7 +720,7 @@ static int edid_read(struct anx7625_data *ctx,
 		ret = sp_tx_aux_rd(ctx, 0xf1);
 
 		if (ret) {
-			sp_tx_rst_aux(ctx);
+			ret = sp_tx_rst_aux(ctx);
 			DRM_DEV_DEBUG_DRIVER(dev, "edid read fail, reset!\n");
 		} else {
 			ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
@@ -735,7 +735,7 @@ static int edid_read(struct anx7625_data *ctx,
 	if (cnt > EDID_TRY_CNT)
 		return -EIO;
 
-	return 0;
+	return ret;
 }
 
 static int segments_edid_read(struct anx7625_data *ctx,
@@ -785,7 +785,7 @@ static int segments_edid_read(struct anx7625_data *ctx,
 	if (cnt > EDID_TRY_CNT)
 		return -EIO;
 
-	return 0;
+	return ret;
 }
 
 static int sp_tx_edid_read(struct anx7625_data *ctx,
@@ -887,7 +887,11 @@ static int sp_tx_edid_read(struct anx7625_data *ctx,
 	}
 
 	/* Reset aux channel */
-	sp_tx_rst_aux(ctx);
+	ret = sp_tx_rst_aux(ctx);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "Failed to reset aux channel!\n");
+		return ret;
+	}
 
 	return (blocks_num + 1);
 }
-- 
2.30.2

[PATCH v2 2/2] drm/bridge: anx7625: Propagate errors from sp_tx_edid_read()

[Robert Foss]

During the sp_tx_edid_read() call the return value of sp_tx_edid_read()
is ignored, which could cause potential errors to go unhandled.

All errors which are returned by sp_tx_edid_read() are handled in
anx7625_get_edid().

Signed-off-by: Robert Foss <robert.foss@linaro.org>
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index ea414cd349b5c..abc8db77bfd36 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -845,8 +845,11 @@ static int sp_tx_edid_read(struct anx7625_data *ctx,
 				if (g_edid_break == 1)
 					break;
 
-				segments_edid_read(ctx, count / 2,
-						   pblock_buf, offset);
+				ret = segments_edid_read(ctx, count / 2,
+							 pblock_buf, offset);
+				if (ret < 0)
+					return ret;
+
 				memcpy(&pedid_blocks_buf[edid_pos],
 				       pblock_buf,
 				       MAX_DPCD_BUFFER_SIZE);
@@ -863,8 +866,11 @@ static int sp_tx_edid_read(struct anx7625_data *ctx,
 				if (g_edid_break == 1)
 					break;
 
-				segments_edid_read(ctx, count / 2,
-						   pblock_buf, offset);
+				ret = segments_edid_read(ctx, count / 2,
+							 pblock_buf, offset);
+				if (ret < 0)
+					return ret;
+
 				memcpy(&pedid_blocks_buf[edid_pos],
 				       pblock_buf,
 				       MAX_DPCD_BUFFER_SIZE);
-- 
2.30.2

Re: [PATCH v2 2/2] drm/bridge: anx7625: Propagate errors from sp_tx_edid_read()

[Robert Foss]

Thanks Sam!

On Wed, 18 Aug 2021 at 19:40, Sam Ravnborg <sam@ravnborg.org> wrote:
>
> Hi Robert,
>
> On Wed, Aug 18, 2021 at 07:13:18PM +0200, Robert Foss wrote:
> > During the sp_tx_edid_read() call the return value of sp_tx_edid_read()
> > is ignored, which could cause potential errors to go unhandled.
> >
> > All errors which are returned by sp_tx_edid_read() are handled in
> > anx7625_get_edid().
> >
> > Signed-off-by: Robert Foss <robert.foss@linaro.org>
> > ---
> >  drivers/gpu/drm/bridge/analogix/anx7625.c | 14 ++++++++++----
> >  1 file changed, 10 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > index ea414cd349b5c..abc8db77bfd36 100644
> > --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > @@ -845,8 +845,11 @@ static int sp_tx_edid_read(struct anx7625_data *ctx,
> >                               if (g_edid_break == 1)
> >                                       break;
> >
> > -                             segments_edid_read(ctx, count / 2,
> > -                                                pblock_buf, offset);
> > +                             ret = segments_edid_read(ctx, count / 2,
> > +                                                      pblock_buf, offset);
> > +                             if (ret < 0)
> > +                                     return ret;
> > +
>
> This could be just "if (ret)".
> Same goes for the next case.
>
> With or without this simplification:
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
>
> I assume you will apply the patches.

Applied to drm-misc-next