On 12/2/24 6:03 PM, Nikolaus Voss wrote:
On 02.12.2024 13:56, Marek Vasut wrote:
On 12/2/24 7:32 AM, Liu Ying wrote:
On 11/27/2024, Nikolaus Voss wrote:
LDB clock has to be a fixed multiple of the pixel clock.
As LDB and pixel clock are derived from different clock sources
(at least on imx8mp), this constraint cannot be satisfied for
any pixel clock, which leads to flickering and incomplete
lines on the attached display.
To overcome this, check this condition in mode_fixup() and
adapt the pixel clock accordingly.
Cc: <stable@xxxxxxxxxxxxxxx>
It looks like stable is not effectively Cc'ed.
Need a Fixes tag?
Isn't this fix effectively superseded by series
[PATCH 0/5] clk: Fix simple video pipelines on i.MX8
?
Maybe. I wasn't aware of the series. Looking at it, the change is
rather complex and not suitable for the stable series.
My intention was to get a simple fix which doesn't potentially
break anything. It wouldn't even break the patch series you mentioned.
I know, the proper fix is indeed complex and not yet fully figured out.
The fix for stable for existing hardware is similar to this commit I think:
4fbb73416b10 ("arm64: dts: imx8mp-phyboard-pollux: Set Video PLL1
frequency to 506.8 MHz")
