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

[Chen-Yu Tsai]

On Wed, Sep 29, 2021 at 5:36 AM Brian Norris <briannorris at chromium.org> 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 at vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris at chromium.org>

Reviewed-by: Chen-Yu Tsai <wenst at chromium.org>