<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - RX460 Memory clock stays high until card is "used"" href="https://bugs.freedesktop.org/show_bug.cgi?id=101528#c2">Comment # 2</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - RX460 Memory clock stays high until card is "used"" href="https://bugs.freedesktop.org/show_bug.cgi?id=101528">bug 101528</a> from <a class="email" href="mailto:alexander@tsoy.me" title="Alexander Tsoy <alexander@tsoy.me>"> Alexander Tsoy</a> <pre>I've added printing of some debug info into smu7_hwmgr.c and here what I get before GPU enters that state: [ 778.701843] AMDGPU: vblank_time_us: 630, switch_limit_us: 450 [ 778.707608] AMDGPU: vblank_time_us: 630, switch_limit_us: 450 [ 778.713379] AMDGPU: disable_mclk_switching: 0, disable_mclk_switching_for_frame_lock: 0, info.display_count: 1, smu7_vblank_too_short: 0, mode_info.refresh_rate: 60 [ 778.748777] AMDGPU: vblank_time_us: 0, switch_limit_us: 450 [ 778.754361] AMDGPU: vblank_time_us: 0, switch_limit_us: 450 [ 778.759951] AMDGPU: disable_mclk_switching: 1, disable_mclk_switching_for_frame_lock: 0, info.display_count: 1, smu7_vblank_too_short: 1, mode_info.refresh_rate: 0 For some reason if refresh_rate = 0 then vblank_time_us = 0. Shouldn't the latter be 0xffffffff instead? So I guess the following commit is the culprit: <a href="https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=09be4a5219610a6fae3215d4f51f948d6f5d2609">https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=09be4a5219610a6fae3215d4f51f948d6f5d2609</a> and the following patch should fix (or workaround?) this issue: - if (vblank_time_us < switch_limit_us) + if (vblank_time_us && (vblank_time_us < switch_limit_us)) After applying it: [ 409.588673] AMDGPU: vblank_time_us: 630, switch_limit_us: 450 [ 409.594427] AMDGPU: vblank_time_us: 630, switch_limit_us: 450 [ 409.600182] AMDGPU: disable_mclk_switching: 0, disable_mclk_switching_for_frame_lock: 0, info.display_count: 1, smu7_vblank_too_short: 0, mode_info.refresh_rate: 60 [ 409.639750] AMDGPU: vblank_time_us: 0, switch_limit_us: 450 [ 409.645321] AMDGPU: vblank_time_us: 0, switch_limit_us: 450 [ 409.650917] AMDGPU: disable_mclk_switching: 0, disable_mclk_switching_for_frame_lock: 0, info.display_count: 1, smu7_vblank_too_short: 0, mode_info.refresh_rate: 0 $ cat /sys/class/drm/card0/device/pp_dpm_mclk 0: 150Mhz * 1: 300Mhz 2: 700Mhz 3: 1450Mhz</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>