[PATCH] drm/mgag200: Increase bandwidth for G200se A rev1

[Roger Sewell]

Thomas,

Thank you for your reply.

>> Table 10 in the following document says that  1440x900 at 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 ?

>> 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.