Re: [PATCH v8 4/8] drm/rockchip: dw-mipi-dsi: Fix error handling path
From: Enric Balletbo i Serra
Date: Fri Mar 02 2018 - 07:23:06 EST
Hi Heiko,
On 02/03/18 13:17, Heiko Stuebner wrote:
> Hi Enric,
>
> Am Freitag, 2. MÃrz 2018, 13:09:02 CET schrieb Enric Balletbo i Serra:
>> Hi Heiko,
>>
>> On 01/03/18 16:50, Heiko StÃbner wrote:
>>> Hi Jeffy, Thierry, Enric,
>>>
>>> Am Mittwoch, 10. Januar 2018, 17:23:44 CET schrieb Thierry Escande:
>>>> From: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
>>>>
>>>> Add missing pm_runtime_disable() in bind()'s error handling path.
>>>>
>>>> Also cleanup encoder & connector in unbind().
>>>
>>> Can you please split all these surprise "Also" sections into separate
>>> patches?
>>>
>>
>> I'll take a look.
>>
>>> It looks like this is true for all following patch to some degree and
>>> the inno-hdmi patch even has a unbind reordering-change without
>>> mentioning it in the commit message.
>>>
>>
>> Actually, I think this patch is not correct against current mainline, see below.
>>
>>>
>>> Thanks
>>> Heiko
>>>
>>>> Fixes: 80a9a059d4e4 ("drm/rockchip/dsi: add dw-mipi power domain support")
>>>> Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
>>>> Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
>>>> ---
>>>> drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 21 +++++++++++++--------
>>>> 1 file changed, 13 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
>>>> b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c index b1fe0639227e..78e6b7919bf7
>>>> 100644
>>>> --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
>>>> +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
>>>> @@ -1282,7 +1282,7 @@ static int dw_mipi_dsi_bind(struct device *dev, struct
>>>> device *master, ret = dw_mipi_dsi_register(drm, dsi);
>>>> if (ret) {
>>>> DRM_DEV_ERROR(dev, "Failed to register mipi_dsi: %d\n", ret);
>>>> - goto err_pllref;
>>>> + goto err_disable_pllref;
>>>> }
>>>>
>>>> dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
>>>> @@ -1290,24 +1290,25 @@ static int dw_mipi_dsi_bind(struct device *dev,
>>>> struct device *master, ret = mipi_dsi_host_register(&dsi->dsi_host);
>>>> if (ret) {
>>>> DRM_DEV_ERROR(dev, "Failed to register MIPI host: %d\n", ret);
>>>> - goto err_cleanup;
>>>> + goto err_disable_pm_runtime;
>>>> }
>>>>
>>>> if (!dsi->panel) {
>>>> ret = -EPROBE_DEFER;
>>>> - goto err_mipi_dsi_host;
>>>> + goto err_unreg_mipi_dsi_host;
>>>> }
>>>>
>>>> dev_set_drvdata(dev, dsi);
>>>> pm_runtime_enable(dev);
>>>> return 0;
>>>>
>>>> -err_mipi_dsi_host:
>>>> +err_unreg_mipi_dsi_host:
>>>> mipi_dsi_host_unregister(&dsi->dsi_host);
>>>> -err_cleanup:
>>>> - drm_encoder_cleanup(&dsi->encoder);
>>>> - drm_connector_cleanup(&dsi->connector);
>>>> -err_pllref:
>>>> +err_disable_pm_runtime:
>>>> + pm_runtime_disable(dev);
>>
>> I think that this is not required, 'pm_runtime_enable' is called just before the
>> 'return 0' (see above). Commit 517f56839f58 'drm/rockchip: dw-mipi-dsi: fix
>> possible un-balanced runtime PM enable' moved the call to that place. So, now
>> the call to pm_runtime_disable is not needed.
>>
>>>> + dsi->connector.funcs->destroy(&dsi->connector);
>>>> + dsi->encoder.funcs->destroy(&dsi->encoder);
>>
>> Here, there is a reordering and also a function replacement. The reorder makes
>> sense to me, first cleanup the connector and then the encoder, but I'm not sure
>> about the function change and if is needed, anyway, in the case is needed,
>> shouldn't be
>>
>> + drm_connector_cleanup(&dsi->connector);
>> + drm_encoder_cleanup(&dsi->encoder);
>>
>> instead?
>
> If you look at drm/rockchip/dw-mipi-dsi.c you'll see that
> dw_mipi_dsi_drm_connector_destroy() does both connector_unregister()
> and drm_connector_cleanup().
>
> And looking at other drivers it really seems that calling that destroy
> callback is really the way to go.
>
Right, thanks for pointing me in the right direction. Learning about this
graphics stuff ;)
Regards,
Enric
>
> Heiko
>