On Mon, Apr 25, 2022 at 01:22:04PM -0400, Alex Deucher wrote: > + dri-devel > > On Mon, Apr 25, 2022 at 3:33 AM Krylov Michael <sqarert@xxxxxxxxx> wrote: > > > > Hello! > > > > After updating my Linux kernel from version 4.19 (Debian 10 version) to > > 5.10 (packaged with Debian 11), I've noticed that the image > > displayed on my older computer, 32-bit Pentium 4 using ATI Radeon X1950 > > AGP video card is severely corrupted in the graphical (Xorg and Wayland) > > mode: all kinds of black and white stripes across the screen, some > > letters missing, etc. > > > > I've checked several options (Xorg drivers, Wayland instead of > > Xorg, radeon.agpmode=-1 in kernel command line and so on), but the > > problem persisted. I've managed to find that the problem was in the > > kernel, as everything worked well with 4.19 kernel with everything > > else being from Debian 11. > > > > I have managed to find the culprit of that corruption, that is the > > commit 33b3ad3788aba846fc8b9a065fe2685a0b64f713 on the linux kernel. > > Reverting this commit and building the kernel with that commit reverted > > fixes the problem. Disabling HIMEM also gets rid of that problem. But it > > also leaves the system with less that 1G of RAM, which is, of course, > > undesirable. > > > > Apparently this problem is somewhat known, as I can tell after googling > > for the commit id, see this link for example: > > https://lkml.org/lkml/2020/1/9/518 > > > > Mageia distro, for example, reverted this commit in the kernel they are > > building: > > > > http://sophie.zarb.org/distrib/Mageia/7/i586/by-pkgid/b9193a4f85192bc57f4d770fb9bb399c/files/32 > > > > I've reported this bug to Debian bugtracker, checked the recent verion > > of the kernel (5.17), bug still persists. Here's a link to the Debian > > bug page: > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=993670 > > > > I'm not sure if reverting this commit is the correct way to go, so if > > you need to check any changes/patches that I could apply and test on > > the real hardware, I'll be glad to do that (but please keep in mind > > that testing could take some time, I don't have access to this computer > > 24/7, but I'll do my best to respond ASAP). > > I would be happy to revert that commit. I attempted to revert it a > year or so ago, but Christoph didn't want to. He was going to look > further into it. I was not able to repro the issue. It seemed to be > related to highmem support. You might try disabling that. Here is > the previous thread for reference: > https://lists.freedesktop.org/archives/amd-gfx/2020-September/053922.html > > Alex So, is there any progress on this issue? I do understand it's not a high priority one, and today I've checked it on 6.0 kernel, and unfortunately, it still persists... I'm considering writing a patch that will allow user to override need_dma32/dma_bits setting with a module parameter. I'll have some time after the New Year for that. Is it at all possible that such a patch will be merged into kernel?
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