[PATCH v3 0/7] drm/bridge_connector: perform HPD enablement automatically

[Dmitry Baryshkov]

Hi,

On 09/01/2023 18:21, Laurentiu Palcu wrote:
> Hi Dmitry,
> 
> It looks like there are some issues with this patchset... :/ I just
> fetched the drm-tip and, with these patches included, the "Hot plug
> detection already enabled" warning is back for i.MX DCSS.

Could you please provide a backtrace?

> 
> After a short investigation, it seems that we end up calling
> drm_bridge_hpd_enable() from both drm_kms_helper_poll_init() and
> drm_fbdev_generic_setup(), hence the warning.
> 
> There are drivers using the drm_bridge_connector API that also call
> drm_kms_helper_poll_init() followed by drm_fbdev_generic_setup(). So,
> they might experience the same behavior, unless I'm missing something...
> :/
> 
> Also, even if drm_fbdev_generic_setup() is not called in the driver
> initialization, the warning will still appear the first time the
> GETCONNECTOR ioctl is called, because that'll call
> drm_helper_probe_single_connector_modes() helper which will eventually
> call drm_bridge_hpd_enable().
> 
> Any idea?
> 
> Cheers,
> Laurentiu
> 
> On Wed, Nov 02, 2022 at 09:06:58PM +0300, Dmitry Baryshkov wrote:
>>  From all the drivers using drm_bridge_connector only iMX/dcss and OMAP
>> DRM driver do a proper work of calling
>> drm_bridge_connector_en/disable_hpd() in right places. Rather than
>> teaching each and every driver how to properly handle
>> drm_bridge_connector's HPD, make that automatic.
>>
>> Add two additional drm_connector helper funcs: enable_hpd() and
>> disable_hpd(). Make drm_kms_helper_poll_* functions call them (as this
>> is the time where the drm_bridge_connector's functions are called by the
>> drivers too).
>>
>> Changes since v2:
>>   - Fixed a typo in the commit message of the second patch.
>>
>> Changes since v1:
>>   - Rebased on top of v6.1-rc1
>>   - Removed the drm_bridge_connector_enable_hpd() from
>>     drm_bridge_connector_init()
>>   - Removed extra underscore prefix from
>>     drm_bridge_connector_en/disable_hpd() helpers
>>
>> Dmitry Baryshkov (7):
>>    drm/poll-helper: merge drm_kms_helper_poll_disable() and _fini()
>>    drm/probe-helper: enable and disable HPD on connectors
>>    drm/bridge_connector: rely on drm_kms_helper_poll_* for HPD enablement
>>    drm/imx/dcss: stop using drm_bridge_connector_en/disable_hpd()
>>    drm/msm/hdmi: stop using drm_bridge_connector_en/disable_hpd()
>>    drm/omap: stop using drm_bridge_connector_en/disable_hpd()
>>    drm/bridge_connector: drop drm_bridge_connector_en/disable_hpd()
>>
>>   drivers/gpu/drm/drm_bridge_connector.c   | 27 +++-------------
>>   drivers/gpu/drm/drm_probe_helper.c       | 40 ++++++++++++++++++-----
>>   drivers/gpu/drm/imx/dcss/dcss-dev.c      |  4 ---
>>   drivers/gpu/drm/imx/dcss/dcss-kms.c      |  2 --
>>   drivers/gpu/drm/msm/hdmi/hdmi.c          |  2 --
>>   drivers/gpu/drm/omapdrm/omap_drv.c       | 41 ------------------------
>>   include/drm/drm_bridge_connector.h       |  2 --
>>   include/drm/drm_modeset_helper_vtables.h | 22 +++++++++++++
>>   8 files changed, 59 insertions(+), 81 deletions(-)
>>
>> -- 
>> 2.35.1
>>

-- 
With best wishes
Dmitry