[PATCH] drm/bridge: ti-sn65dsi86: Associate DSI device lifetime with auxiliary device

[PATCH] drm/bridge: ti-sn65dsi86: Associate DSI device lifetime with auxiliary device

[Stephen Boyd]

The kernel produces a warning splat and the DSI device fails to register
in this driver if the i2c driver probes, populates child auxiliary
devices, and then somewhere in ti_sn_bridge_probe() a function call
returns -EPROBE_DEFER. When the auxiliary driver probe defers, the dsi
device created by devm_mipi_dsi_device_register_full() is left
registered because the devm managed device used to manage the lifetime
of the DSI device is the parent i2c device, not the auxiliary device
that is being probed.

Associate the DSI device created and managed by this driver to the
lifetime of the auxiliary device, not the i2c device, so that the DSI
device is removed when the auxiliary driver unbinds. Similarly change
the device pointer used for dev_err_probe() so the deferred probe errors
are associated with the auxiliary device instead of the parent i2c
device so we can narrow down future problems faster.

Cc: Douglas Anderson <dianders@chromium.org>
Cc: Maxime Ripard <maxime@cerno.tech>
Fixes: c3b75d4734cb ("drm/bridge: sn65dsi86: Register and attach our DSI device at probe")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/gpu/drm/bridge/ti-sn65dsi86.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index f448b903e190..84148a79414b 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -692,7 +692,7 @@ static struct ti_sn65dsi86 *bridge_to_ti_sn65dsi86(struct drm_bridge *bridge)
 	return container_of(bridge, struct ti_sn65dsi86, bridge);
 }
 
-static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
+static int ti_sn_attach_host(struct auxiliary_device *adev, struct ti_sn65dsi86 *pdata)
 {
 	int val;
 	struct mipi_dsi_host *host;
@@ -707,7 +707,7 @@ static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
 	if (!host)
 		return -EPROBE_DEFER;
 
-	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
+	dsi = devm_mipi_dsi_device_register_full(&adev->dev, host, &info);
 	if (IS_ERR(dsi))
 		return PTR_ERR(dsi);
 
@@ -725,7 +725,7 @@ static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
 
 	pdata->dsi = dsi;
 
-	return devm_mipi_dsi_attach(dev, dsi);
+	return devm_mipi_dsi_attach(&adev->dev, dsi);
 }
 
 static int ti_sn_bridge_attach(struct drm_bridge *bridge,
@@ -1298,9 +1298,9 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev,
 	struct device_node *np = pdata->dev->of_node;
 	int ret;
 
-	pdata->next_bridge = devm_drm_of_get_bridge(pdata->dev, np, 1, 0);
+	pdata->next_bridge = devm_drm_of_get_bridge(&adev->dev, np, 1, 0);
 	if (IS_ERR(pdata->next_bridge))
-		return dev_err_probe(pdata->dev, PTR_ERR(pdata->next_bridge),
+		return dev_err_probe(&adev->dev, PTR_ERR(pdata->next_bridge),
 				     "failed to create panel bridge\n");
 
 	ti_sn_bridge_parse_lanes(pdata, np);
@@ -1319,9 +1319,9 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev,
 
 	drm_bridge_add(&pdata->bridge);
 
-	ret = ti_sn_attach_host(pdata);
+	ret = ti_sn_attach_host(adev, pdata);
 	if (ret) {
-		dev_err_probe(pdata->dev, ret, "failed to attach dsi host\n");
+		dev_err_probe(&adev->dev, ret, "failed to attach dsi host\n");
 		goto err_remove_bridge;
 	}
 

base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
-- 
https://chromeos.dev

Re: [PATCH] drm/bridge: ti-sn65dsi86: Associate DSI device lifetime with auxiliary device

[Doug Anderson]

Hi,

On Mon, Oct 2, 2023 at 4:54 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> The kernel produces a warning splat and the DSI device fails to register
> in this driver if the i2c driver probes, populates child auxiliary
> devices, and then somewhere in ti_sn_bridge_probe() a function call
> returns -EPROBE_DEFER. When the auxiliary driver probe defers, the dsi
> device created by devm_mipi_dsi_device_register_full() is left
> registered because the devm managed device used to manage the lifetime
> of the DSI device is the parent i2c device, not the auxiliary device
> that is being probed.
>
> Associate the DSI device created and managed by this driver to the
> lifetime of the auxiliary device, not the i2c device, so that the DSI
> device is removed when the auxiliary driver unbinds. Similarly change
> the device pointer used for dev_err_probe() so the deferred probe errors
> are associated with the auxiliary device instead of the parent i2c
> device so we can narrow down future problems faster.
>
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: Maxime Ripard <maxime@cerno.tech>
> Fixes: c3b75d4734cb ("drm/bridge: sn65dsi86: Register and attach our DSI device at probe")

Even before that commit I think it was using the main "dev" instead of
the auxiliary device's "dev" for some "devm" stuff. I guess the
difference is that it wouldn't mess with probe deferral? Searching
back, I think the first instance of a case that was using "devm_" with
the wrong device was commit 4e5763f03e10 ("drm/bridge: ti-sn65dsi86:
Wrap panel with panel-bridge")? Would it make sense to use that as a
Fixes, you think?

In any case, this looks reasonable to me:

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

I'll give it a week and then apply to "-fixes" if everything is quiet.

Re: [PATCH] drm/bridge: ti-sn65dsi86: Associate DSI device lifetime with auxiliary device

[Stephen Boyd]

Quoting Doug Anderson (2023-10-02 17:31:41)
> Hi,
>
> On Mon, Oct 2, 2023 at 4:54 PM Stephen Boyd <swboyd@chromium.org> wrote:
> >
> > The kernel produces a warning splat and the DSI device fails to register
> > in this driver if the i2c driver probes, populates child auxiliary
> > devices, and then somewhere in ti_sn_bridge_probe() a function call
> > returns -EPROBE_DEFER. When the auxiliary driver probe defers, the dsi
> > device created by devm_mipi_dsi_device_register_full() is left
> > registered because the devm managed device used to manage the lifetime
> > of the DSI device is the parent i2c device, not the auxiliary device
> > that is being probed.
> >
> > Associate the DSI device created and managed by this driver to the
> > lifetime of the auxiliary device, not the i2c device, so that the DSI
> > device is removed when the auxiliary driver unbinds. Similarly change
> > the device pointer used for dev_err_probe() so the deferred probe errors
> > are associated with the auxiliary device instead of the parent i2c
> > device so we can narrow down future problems faster.
> >
> > Cc: Douglas Anderson <dianders@chromium.org>
> > Cc: Maxime Ripard <maxime@cerno.tech>
> > Fixes: c3b75d4734cb ("drm/bridge: sn65dsi86: Register and attach our DSI device at probe")
>
> Even before that commit I think it was using the main "dev" instead of
> the auxiliary device's "dev" for some "devm" stuff. I guess the
> difference is that it wouldn't mess with probe deferral? Searching
> back, I think the first instance of a case that was using "devm_" with
> the wrong device was commit 4e5763f03e10 ("drm/bridge: ti-sn65dsi86:
> Wrap panel with panel-bridge")? Would it make sense to use that as a
> Fixes, you think?

The problem for me is that the dsi device is registered twice. That
happens because probe for the auxiliary device happens twice. I was
cautious about the fixes tag here because it didn't look like probe
deferral was happening before commit c3b75d4734cb.

>
> In any case, this looks reasonable to me:
>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
>
> I'll give it a week and then apply to "-fixes" if everything is quiet.

Thanks!

Re: [PATCH] drm/bridge: ti-sn65dsi86: Associate DSI device lifetime with auxiliary device

[Doug Anderson]

Hi,

On Thu, Oct 5, 2023 at 10:18 AM Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Doug Anderson (2023-10-02 17:31:41)
> > Hi,
> >
> > On Mon, Oct 2, 2023 at 4:54 PM Stephen Boyd <swboyd@chromium.org> wrote:
> > >
> > > The kernel produces a warning splat and the DSI device fails to register
> > > in this driver if the i2c driver probes, populates child auxiliary
> > > devices, and then somewhere in ti_sn_bridge_probe() a function call
> > > returns -EPROBE_DEFER. When the auxiliary driver probe defers, the dsi
> > > device created by devm_mipi_dsi_device_register_full() is left
> > > registered because the devm managed device used to manage the lifetime
> > > of the DSI device is the parent i2c device, not the auxiliary device
> > > that is being probed.
> > >
> > > Associate the DSI device created and managed by this driver to the
> > > lifetime of the auxiliary device, not the i2c device, so that the DSI
> > > device is removed when the auxiliary driver unbinds. Similarly change
> > > the device pointer used for dev_err_probe() so the deferred probe errors
> > > are associated with the auxiliary device instead of the parent i2c
> > > device so we can narrow down future problems faster.
> > >
> > > Cc: Douglas Anderson <dianders@chromium.org>
> > > Cc: Maxime Ripard <maxime@cerno.tech>
> > > Fixes: c3b75d4734cb ("drm/bridge: sn65dsi86: Register and attach our DSI device at probe")
> >
> > Even before that commit I think it was using the main "dev" instead of
> > the auxiliary device's "dev" for some "devm" stuff. I guess the
> > difference is that it wouldn't mess with probe deferral? Searching
> > back, I think the first instance of a case that was using "devm_" with
> > the wrong device was commit 4e5763f03e10 ("drm/bridge: ti-sn65dsi86:
> > Wrap panel with panel-bridge")? Would it make sense to use that as a
> > Fixes, you think?
>
> The problem for me is that the dsi device is registered twice. That
> happens because probe for the auxiliary device happens twice. I was
> cautious about the fixes tag here because it didn't look like probe
> deferral was happening before commit c3b75d4734cb.
>
> >
> > In any case, this looks reasonable to me:
> >
> > Reviewed-by: Douglas Anderson <dianders@chromium.org>
> >
> > I'll give it a week and then apply to "-fixes" if everything is quiet.
>
> Thanks!

Pushed to drm-misc-fixes leaving your existing "Fixes" line:

7b821db95140 drm/bridge: ti-sn65dsi86: Associate DSI device lifetime
with auxiliary device

-Doug

Re: [PATCH] drm/bridge: ti-sn65dsi86: Associate DSI device lifetime with auxiliary device

[Neil Armstrong]

On 03/10/2023 01:54, Stephen Boyd wrote:
> The kernel produces a warning splat and the DSI device fails to register
> in this driver if the i2c driver probes, populates child auxiliary
> devices, and then somewhere in ti_sn_bridge_probe() a function call
> returns -EPROBE_DEFER. When the auxiliary driver probe defers, the dsi
> device created by devm_mipi_dsi_device_register_full() is left
> registered because the devm managed device used to manage the lifetime
> of the DSI device is the parent i2c device, not the auxiliary device
> that is being probed.
> 
> Associate the DSI device created and managed by this driver to the
> lifetime of the auxiliary device, not the i2c device, so that the DSI
> device is removed when the auxiliary driver unbinds. Similarly change
> the device pointer used for dev_err_probe() so the deferred probe errors
> are associated with the auxiliary device instead of the parent i2c
> device so we can narrow down future problems faster.
> 
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: Maxime Ripard <maxime@cerno.tech>
> Fixes: c3b75d4734cb ("drm/bridge: sn65dsi86: Register and attach our DSI device at probe")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>   drivers/gpu/drm/bridge/ti-sn65dsi86.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> index f448b903e190..84148a79414b 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -692,7 +692,7 @@ static struct ti_sn65dsi86 *bridge_to_ti_sn65dsi86(struct drm_bridge *bridge)
>   	return container_of(bridge, struct ti_sn65dsi86, bridge);
>   }
>   
> -static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
> +static int ti_sn_attach_host(struct auxiliary_device *adev, struct ti_sn65dsi86 *pdata)
>   {
>   	int val;
>   	struct mipi_dsi_host *host;
> @@ -707,7 +707,7 @@ static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
>   	if (!host)
>   		return -EPROBE_DEFER;
>   
> -	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
> +	dsi = devm_mipi_dsi_device_register_full(&adev->dev, host, &info);
>   	if (IS_ERR(dsi))
>   		return PTR_ERR(dsi);
>   
> @@ -725,7 +725,7 @@ static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
>   
>   	pdata->dsi = dsi;
>   
> -	return devm_mipi_dsi_attach(dev, dsi);
> +	return devm_mipi_dsi_attach(&adev->dev, dsi);
>   }
>   
>   static int ti_sn_bridge_attach(struct drm_bridge *bridge,
> @@ -1298,9 +1298,9 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev,
>   	struct device_node *np = pdata->dev->of_node;
>   	int ret;
>   
> -	pdata->next_bridge = devm_drm_of_get_bridge(pdata->dev, np, 1, 0);
> +	pdata->next_bridge = devm_drm_of_get_bridge(&adev->dev, np, 1, 0);
>   	if (IS_ERR(pdata->next_bridge))
> -		return dev_err_probe(pdata->dev, PTR_ERR(pdata->next_bridge),
> +		return dev_err_probe(&adev->dev, PTR_ERR(pdata->next_bridge),
>   				     "failed to create panel bridge\n");
>   
>   	ti_sn_bridge_parse_lanes(pdata, np);
> @@ -1319,9 +1319,9 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev,
>   
>   	drm_bridge_add(&pdata->bridge);
>   
> -	ret = ti_sn_attach_host(pdata);
> +	ret = ti_sn_attach_host(adev, pdata);
>   	if (ret) {
> -		dev_err_probe(pdata->dev, ret, "failed to attach dsi host\n");
> +		dev_err_probe(&adev->dev, ret, "failed to attach dsi host\n");
>   		goto err_remove_bridge;
>   	}
>   
> 
> base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d

This looks reasonable

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>