Re: [PATCH v3 2/4] drm/rockchip: dsi: Reconfigure hardware on resume()

[Nícolas F. R. A. Prado]

On Tue, Sep 28, 2021 at 02:35:50PM -0700, Brian Norris wrote:
> Since commit 43c2de1002d2, we perform most HW configuration in the
> bind() function. This configuration may be lost on suspend/resume, so we
> need to call it again. That may lead to errors like this after system
> suspend/resume:
> 
>   dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
>   panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110
> 
> Tested on Acer Chromebook Tab 10 (RK3399 Gru-Scarlet).
> 
> Note that early mailing list versions of this driver borrowed Rockchip's
> downstream/BSP solution, to do HW configuration in mode_set() (which
> *is* called at the appropriate pre-enable() times), but that was
> discarded along the way. I've avoided that still, because mode_set()
> documentation doesn't suggest this kind of purpose as far as I can tell.
> 
> Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>

Tested-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>