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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 3/2/20 10:13 PM, Brian Masney wrote:
On Mon, Mar 02, 2020 at 03:48:22PM -0500, Jonathan Marek wrote:
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)

Is this the right clock frequency in the downstream MSM 3.4 kernel that
you're talking about?

https://github.com/AICP/kernel_lge_hammerhead/blob/n7.1/arch/arm/mach-msm/clock-8974.c#L3326


No, I'm talking about the DSI clock (the driver for it is in drm/msm/dsi/). For a command mode panel the front/back porches aren't relevant, but the dsi pixel/byte clock need to be a bit higher than 1920x1080x60. Since 125498 is a little higher than 124416 that might be enough (there is also rounding of the clock values to consider).

I don't see any obvious clock values in the downstream command mode
panel configuration:

https://github.com/AICP/kernel_lge_hammerhead/blob/n7.1/arch/arm/boot/dts/msm8974-hammerhead/msm8974-hammerhead-panel.dtsi#L591

Anyways, I tried Ville's patch with the framebuffer, kmscube, and X11
and everything appears to be working fine. You can add my Tested-by if
you end up applying this.

Tested-by: Brian Masney <masneyb@xxxxxxxxxxxxx>

Brian


On 3/2/20 3:34 PM, Ville Syrjala wrote:
From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>

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@xxxxxxxx>
Cc: Brian Masney <masneyb@xxxxxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
   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,

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux