2019-06-10 17:53:25

by Doug Anderson

Subject: [PATCH] drm/bridge/synopsys: dw-hdmi: Fix unwedge crash when no pinctrl entries

In commit 50f9495efe30 ("drm/bridge/synopsys: dw-hdmi: Add "unwedge"
for ddc bus") I stupidly used IS_ERR() to check for whether we have an
"unwedge" pinctrl state even though on most flows through the driver
the unwedge state will just be NULL.

Fix it so that we consistently use NULL for no unwedge state.

Fixes: 50f9495efe30 ("drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus")
Reported-by: Erico Nunes <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
---

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index f25e091b93c5..5e4e9408d00f 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -251,7 +251,7 @@ static void dw_hdmi_i2c_init(struct dw_hdmi *hdmi)
static bool dw_hdmi_i2c_unwedge(struct dw_hdmi *hdmi)
{
/* If no unwedge state then give up */
- if (IS_ERR(hdmi->unwedge_state))
+ if (!hdmi->unwedge_state)
return false;

dev_info(hdmi->dev, "Attempting to unwedge stuck i2c bus\n");
@@ -2686,11 +2686,13 @@ __dw_hdmi_probe(struct platform_device *pdev,
hdmi->default_state =
pinctrl_lookup_state(hdmi->pinctrl, "default");

- if (IS_ERR(hdmi->default_state) &&
- !IS_ERR(hdmi->unwedge_state)) {
- dev_warn(dev,
- "Unwedge requires default pinctrl\n");
- hdmi->unwedge_state = ERR_PTR(-ENODEV);
+ if (IS_ERR(hdmi->default_state) ||
+ IS_ERR(hdmi->unwedge_state)) {
+ if (!IS_ERR(hdmi->unwedge_state))
+ dev_warn(dev,
+ "Unwedge requires default pinctrl\n");
+ hdmi->default_state = NULL;
+ hdmi->unwedge_state = NULL;
}
}

--
2.22.0.rc2.383.gf4fbbf30c2-goog

2019-06-10 20:52:53

by Sean Paul

Subject: Re: [PATCH] drm/bridge/synopsys: dw-hdmi: Fix unwedge crash when no pinctrl entries

On Mon, Jun 10, 2019 at 1:52 PM Douglas Anderson <[email protected]> wrote:
>
> In commit 50f9495efe30 ("drm/bridge/synopsys: dw-hdmi: Add "unwedge"
> for ddc bus") I stupidly used IS_ERR() to check for whether we have an
> "unwedge" pinctrl state even though on most flows through the driver
> the unwedge state will just be NULL.
>
> Fix it so that we consistently use NULL for no unwedge state.
>
> Fixes: 50f9495efe30 ("drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus")
> Reported-by: Erico Nunes <[email protected]>
> Signed-off-by: Douglas Anderson <[email protected]>

Thanks Erico for the report, and Doug for fixing this up quickly, I've applied
the patch to drm-misc-next

Sean

> ---
>
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index f25e091b93c5..5e4e9408d00f 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -251,7 +251,7 @@ static void dw_hdmi_i2c_init(struct dw_hdmi *hdmi)
> static bool dw_hdmi_i2c_unwedge(struct dw_hdmi *hdmi)
> {
> /* If no unwedge state then give up */
> - if (IS_ERR(hdmi->unwedge_state))
> + if (!hdmi->unwedge_state)
> return false;
>
> dev_info(hdmi->dev, "Attempting to unwedge stuck i2c bus\n");
> @@ -2686,11 +2686,13 @@ __dw_hdmi_probe(struct platform_device *pdev,
> hdmi->default_state =
> pinctrl_lookup_state(hdmi->pinctrl, "default");
>
> - if (IS_ERR(hdmi->default_state) &&
> - !IS_ERR(hdmi->unwedge_state)) {
> - dev_warn(dev,
> - "Unwedge requires default pinctrl\n");
> - hdmi->unwedge_state = ERR_PTR(-ENODEV);
> + if (IS_ERR(hdmi->default_state) ||
> + IS_ERR(hdmi->unwedge_state)) {
> + if (!IS_ERR(hdmi->unwedge_state))
> + dev_warn(dev,
> + "Unwedge requires default pinctrl\n");
> + hdmi->default_state = NULL;
> + hdmi->unwedge_state = NULL;
> }
> }
>
> --
> 2.22.0.rc2.383.gf4fbbf30c2-goog
>

2019-06-11 12:26:46

by Erico Nunes

Subject: Re: [PATCH] drm/bridge/synopsys: dw-hdmi: Fix unwedge crash when no pinctrl entries

On Mon, Jun 10, 2019 at 10:51 PM Sean Paul <[email protected]> wrote:
>
> On Mon, Jun 10, 2019 at 1:52 PM Douglas Anderson <[email protected]> wrote:
> >
> > In commit 50f9495efe30 ("drm/bridge/synopsys: dw-hdmi: Add "unwedge"
> > for ddc bus") I stupidly used IS_ERR() to check for whether we have an
> > "unwedge" pinctrl state even though on most flows through the driver
> > the unwedge state will just be NULL.
> >
> > Fix it so that we consistently use NULL for no unwedge state.
> >
> > Fixes: 50f9495efe30 ("drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus")
> > Reported-by: Erico Nunes <[email protected]>
> > Signed-off-by: Douglas Anderson <[email protected]>
>
> Thanks Erico for the report, and Doug for fixing this up quickly, I've applied
> the patch to drm-misc-next

It does fix the issue. Thank you for the quick fix.

Erico