https://bugs.freedesktop.org/show_bug.cgi?id=48422
Bug #: 48422 Summary: Radeon KMS fails on Radeon X850XT (R480) graphics card Classification: Unclassified Product: DRI Version: XOrg 6.7.0 Platform: x86-64 (AMD64) OS/Version: All Status: NEW Severity: normal Priority: medium Component: DRM/Radeon AssignedTo: dri-devel@lists.freedesktop.org ReportedBy: mike@coruscant.demon.co.uk
Created attachment 59628 --> https://bugs.freedesktop.org/attachment.cgi?id=59628 Dmesg output from boot
Video output fails completely (apparently due to a KMS regression) on all kernels >= 3.2, rendering the system unusable as a desktop. Access via SSH over network is unaffected.
Steps to reproduce: Boot any recent kernel. This has been encountered with Debian, and the kernel versions in question are:-
linux-image-3.0.0-2-amd64 3.0.0-5 functions as expected linux-image-3.2.0-1-amd64 3.2.7-1 fails linux-image-3.2.0-2-amd64 3.2.13-1 fails linux-image-3.3.0-trunk-amd64 3.3-1~experimental.1 fails
Expected behaviour:-
At system boot, initial kernel output appears on the VGA console, until the drm driver is loaded, when the kernel switches the output font and resolution. Boot continues until a subsequent switch (I believe when the kernel attempts to modeswitch the card), at which point the font visibly changes at this point and boot continues, with further console output until the X desktop appears.
Actual behaviour with failing kernels:-
Boot starts normally until the modeswitch happens, at which point video output ceases, and the monitor shows no signal on the DVI input.
Graphics hardware details from lspci is:-
01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI R480 [Radeon X850XT (PCIE)] (Primary) 01:00.1 Display controller: Advanced Micro Devices [AMD] nee ATI R480 [Radeon X850XT (PCIE)] (Secondary)
Attached file is dmesg output from booting the 3.3 kernel with drm.debug=0x6 passed as a kernel parameter.