On 25/07/2023 23:31, Roger Sewell wrote:
Thomas,
Thank you for your reply.
Table 10 in the following document says that 1440x900@60Hz is
supported:
https://www.intel.com/content/dam/support/us/en/documents/motherboards/server/s5520ur/sb/e44031012_s5520ur_s5520urt_tps_r1_9.pdf
That manual says that the resolution is only supported with at most
24-bit colors. The old X code still supports that to some extend, but
modern userspace doesn't.
How can I check for sure whether I am using 24 or 32 bits per pixel ?
The easiest solution if you already rebuilt your kernel is to print the
variable bpp here:
https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/mgag200/mgag200_mode.c#L326
pr_info("mgag200 bpp %d\n", bpp);
Also if you can run Wayland at 1440x900@60, that would mean the hardware
is indeed able to handle it in 32bit.
so in particular the chip is said to be a G200e, not the G200SE-A
that the kernel module seems to be interpreting it as.
It actually is the G200SE-A. It's just named differently by lspci. The
PCI device id should be 0x0522.
It is indeed 0x0522.
So the old kernel already did the right thing.
(but if I understand the situation right Xorg didn't ?)
You can do
cat /sys/class/drm/card1-VGA-1/modes
on the old and new kernel. With a monitor connector, it will tell you
the supported resolutions.
With the new kernel and the unmodified mgag200 module it tells me that
1440x900 is not on the list - but Xorg still lists it under
Settings->Display (and Wayland doesn't). With the increased bandwidth
module in place it tells me 1440x900 is on the list. I think this is as
you expect as far as the kernel rather than Xorg is concerned.
Thanks,
Roger.
Best regards,
--
Jocelyn
