On 24.04.2023 12:00, Adam Ford wrote: > On Mon, Apr 24, 2023 at 3:25 AM Marek Szyprowski > <m.szyprowski@xxxxxxxxxxx> wrote: >> On 23.04.2023 14:12, Adam Ford wrote: >>> The high-speed clock is hard-coded to the burst-clock >>> frequency specified in the device tree. However, when >>> using devices like certain bridge chips without burst mode >>> and varying resolutions and refresh rates, it may be >>> necessary to set the high-speed clock dynamically based >>> on the desired pixel clock for the connected device. >>> >>> This also removes the need to set a clock speed from >>> the device tree for non-burst mode operation, since the >>> pixel clock rate is the rate requested from the attached >>> device like an HDMI bridge chip. This should have no >>> impact for people using burst-mode and setting the burst >>> clock rate is still required for those users. >>> >>> Signed-off-by: Adam Ford <aford173@xxxxxxxxx> >> This one breaks Exynos-5433 based TM2e board with a DSI panel. > Marek S, > > Thank you for testing! I knoiw there are several of us who appreciate > your testing this since it's hard to know if something broke without > hardware. Is there any way you can tell me if the flag is set to > enable MIPI_DSI_MODE_VIDEO_BURST? TM2e board uses the DSI panel operated in command mode and handled by panel-samsung-s6e3ha2.c driver. The MIPI_DSI_MODE_VIDEO_BURST flag is not set by the driver. However, the MIPI_DSI_CLOCK_NON_CONTINUOUS flags is set there. I really have no idea if setting VIDEO_BURST would make sense together with CLOCK_NON_CONTINUOUS or not. Maybe the driver lacks setting it? > I was trying to be diligent about not breaking your boards, but > without your boards, it's difficult. The theory was that if > MIPI_DSI_MODE_VIDEO_BURST is set and there is a burst clock set in the > device tree, it would use the burst clock. > > As a fall-back I could just simply check for the presence of the > burst_clock_rate instead of both MIPI_DSI_MODE_VIDEO_BURST and > burst_clock_rate. Maybe you should extend your check also for the MIPI_DSI_CLOCK_NON_CONTINUOUS flag? Does it make sense? > ... Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
