[PATCH v2 1/2] drm/panel: Remove drm_panel_detach() calls from all panel drives

[Jyri Sarha]

On 28/02/18 20:53, Thierry Reding wrote:
> On Wed, Feb 28, 2018 at 01:09:29PM +0200, Jyri Sarha wrote:
>> Setting the connector and drm to NULL when the drm panel device is
>> going away hardly serves any purpose. Usually the the whole memory
>> stucture is freed right after the remove call.
>>
>> Signed-off-by: Jyri Sarha <jsarha at ti.com>
>> ---
>>  drivers/gpu/drm/panel/panel-innolux-p079zca.c        | 1 -
>>  drivers/gpu/drm/panel/panel-jdi-lt070me05000.c       | 1 -
>>  drivers/gpu/drm/panel/panel-lvds.c                   | 1 -
>>  drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c | 1 -
>>  drivers/gpu/drm/panel/panel-seiko-43wvf1g.c          | 1 -
>>  drivers/gpu/drm/panel/panel-sharp-lq101r1sx01.c      | 1 -
>>  drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c      | 1 -
>>  drivers/gpu/drm/panel/panel-simple.c                 | 1 -
>>  drivers/gpu/drm/panel/panel-sitronix-st7789v.c       | 1 -
>>  9 files changed, 9 deletions(-)
> 
> I don't understand the purpose of this patch. I'll grant you that the
> current implementation of drm_panel_detach() is not very useful, but
> then you add code to drm_panel_detach() in the next patch and mention
> in the commit message that panel drivers should be calling the
> drm_panel_detach() function to remove the link.
> 
> This is confusing. Can you clarify?
> 

When looking at the current implementation it does not make any sense to
me to call drm_panel_detach() from the panel driver itself. However, it
makes perfect sense calling it from drm driver. Setting panel->connector
= NULL marks it free and attachable to other devices, but the panel
driver that the passive element in the picture should not go and mark
itself available on its own.

But now that I take the steps to make the drm_panel_detach() to be
called only from drm device I should at least document it too.

Also in general I think it is hard to come up with a detach
implementation that would work from both panel and the drm device.

Best regards,
Jyri

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