Created attachment 250851 [details] A8-7600 dmesg (full) UVD init fails at boot and and X server starting stops. Terminal works but rebooting is impossible because of lightdm has hanged. Hardware: Amd A8-7600 APU, Gigabyte F2A88XM-DS2 motherboard, single 4GB ddr3 2133Mhz ram stick. OS: Debian testing Xfce. When using X4 845 and RX460 I have same UVD errors at boot, but X starts ok and the computer works ok. Adding _netdev to /etc/fstab home partition mount options helps to start X with A8-7600 (errors still present at boot and shutdown) and with X4 845 and RX460 removes UVD errors completely. Setting #define AMD_MAX_USEC_TIMEOUT to 100 ms is better value for A8-7600 than 200 ms because 100ms value enables X to start, see drivers/gpu/drm/amd/include/amd_shared.h. The same problem is with agd5f/linux/log/drivers/gpu/drm/amd?h=drm-next-4.10-wip kernel that is in 4.9-rc8 now. When it it was in version 4.9-rc2 the driver did work fine in both computers. With A8-7600 pc we need to use the stock Debian kernel 4.8 radeon kernel driver now.
See also: https://bugs.freedesktop.org/show_bug.cgi?id=99313 Rex is working on a fix.
I am using latest agd5f drm-next-4.11-wip kernel and amdgpu driver works fine with A8-7600 and RX460. https://cgit.freedesktop.org/~agd5f/linux/commit/drivers/gpu/drm/amd?h=drm-next-4.11-wip&id=0153b4f9fd9d7cf3e6ddebd8ee3510955c376030 Thanks to Amd for fast bug fixing.