Re: [PATCH 33/33] drm/panel-simple: Fix dotclock for LG ACX467AKM-7

Jonathan Marek
2020-03-03T08:25:36Z

Hi,

This is a command mode panel and the the msm/mdp5 driver uses the
vrefresh field for the actual refresh rate, while the dotclock field is
used for the DSI clocks. The dotclock needed to be a bit higher than
necessary otherwise the panel would not work.

If you want to get rid of the separate clock/vrefresh fields there would
need to be some changes to msm driver.

(note I hadn't made the patch with upstreaming in mind, the 150000 value
is likely not optimal, just something that worked, this is something
that should have been checked with the downstream driver)

-Jonathan

On 3/2/20 3:34 PM, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> The currently listed dotclock disagrees with the currently
> listed vrefresh rate. Change the dotclock to match the vrefresh.
>
> Someone tell me which (if either) of the dotclock or vreresh is
> correct?
>
> Cc: Jonathan Marek <jonathan@marek.ca>
> Cc: Brian Masney <masneyb@onstation.org>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/gpu/drm/panel/panel-simple.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index b24fdf239440..f958d8dfd760 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -3996,7 +3996,7 @@ static const struct panel_desc_dsi panasonic_vvx10f004b00 = {
> };
>
> static const struct drm_display_mode lg_acx467akm_7_mode = {
> - .clock = 150000,
> + .clock = 125498,
> .hdisplay = 1080,
> .hsync_start = 1080 + 2,
> .hsync_end = 1080 + 2 + 2,