Re: [PATCH 1/2] drm/rockchip: dw_hdmi: relax mode_valid hook

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

 



On Wed, Aug 24, 2022 at 05:07:50PM +0100, Robin Murphy wrote:
> On 2022-08-22 16:20, Sascha Hauer wrote:
> > The driver checks if the pixel clock of the given mode matches an entry
> > in the mpll config table. The frequencies in the mpll table are meant as
> > a frequency range up to which the entry works, not as a frequency that
> > must match the pixel clock. Return MODE_OK when the pixelclock is
> > smaller than one of the mpll frequencies to allow for more display
> > resolutions.
> 
> Has the issue been fixed that this table is also used to validate modes on
> RK3328, which doesn't even *have* the Synopsys phy? Last time I looked, that
> tended to lead to complete display breakage when the proper phy driver later
> decides it doesn't like a pixel clock that mode_valid already said was OK.
> 
> The more general concern is that these known-good clock rates are good, but
> others may not be even when nominally supported, which I suspect is the
> dirty secret of why it was implemented this way to begin with. I would
> really really love this patch so my RK3399 board can drive my 1920x1200
> monitor at native resolution, but on the other hand my RK3288 box generates
> such a crap 154MHz clock for that mode that - unless that's been improved in
> the meantime too - patch #2 might be almost be considered a regression if it
> means such a setup would start defaulting to an unusably glitchy display
> instead of falling back to 1920x1080 which does at least work perfectly
> (even if the slightly squished aspect ratio is ugly).

I could limit the change to rk3568 only. Would that be an option?
Not sure if I should rk3399 as well then as this would work, at least in
your setup.

Sascha

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |



[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