• Imre Deak's avatar
    drm/i915/icl: Disable DIP on MST ports with the transcoder clock still on · c980216d
    Imre Deak authored
    According to BSpec the Data Island Packet should be disabled after
    disabling the transcoder, but before the transcoder clock select is set
    to none. On an ICL RVP, daisy-chained MST config not following this
    leads to a hang with the following MCE when disabling the output:
    
    [  870.948739] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 6: ba00000011000402
    [  871.019212] mce: [Hardware Error]: RIP !INEXACT! 10:<ffffffff81aca652> {poll_idle+0x92/0xb0}
    [  871.019212] mce: [Hardware Error]: TSC 135a261fe61
    [  871.019212] mce: [Hardware Error]: PROCESSOR 0:706e5 TIME 1591739604 SOCKET 0 APIC 0 microcode 20
    [  871.019212] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
    [  871.019212] mce: [Hardware Error]: Machine check: Processor context corrupt
    [  871.019212] Kernel panic - not syncing: Fatal machine check
    [  871.019212] Kernel Offset: disabled
    
    Bspec: 4287
    
    Fixes: fa37a213 ("drm/i915: Stop sending DP SDPs on ddi disable")
    Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
    Cc: Uma Shankar <uma.shankar@intel.com>
    Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
    Reviewed-by: default avatarUma Shankar <uma.shankar@intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20200609220616.6015-1-imre.deak@intel.com
    c980216d
intel_dp_mst.c 28 KB