| Message ID | 20211215041123.106364-1-koba.ko@canonical.com |
|---|---|
| Headers | show |
| Series | Fix System hangs on black screen when reboot | expand |
On Wed, Dec 15, 2021 at 12:11:20PM +0800, Koba Ko wrote: > BugLink: https://bugs.launchpad.net/bugs/1949321 > > [Impact] > System hangs on black screen when reboot > > [Fix] > Looks like our VBIOS/GOP generally fail to turn the DP dual mode adater > TMDS output buffers back on after a reboot. This leads to a black screen > after reboot if we turned the TMDS output buffers off prior to reboot. > And if i915 decides to do a fastboot the black screen will persist even > after i915 takes over. > > Apparently this has been a problem ever since commit b2ccb822d376 ("drm/i915:Enable/disable TMDS output buffers in DP++ adaptor as needed") if one rebooted while the display was turned off. And things became worse with commit fe0f1e3bfdfe ("drm/i915: Shut down displays gracefully on reboot") since now we always turn the display off before a reboot. > > This was reported on a RKL, but I confirmed the same behaviour on my > SNB as well. So looks pretty universal. > > Let's fix this by explicitly turning the TMDS output buffers back on > in the encoder->shutdown() hook. Note that this gets called after irqs > have been disabled, so the i2c communication with the DP dual mode > adapter has to be performed via polling (which the gmbus code is > perfectly happy to do for us). > > We also need a bit of care in handling DDI encoders which may or may > not be set up for HDMI output. Specifically ddc_pin will not be > populated for a DP only DDI encoder, in which case we don't want to > call intel_gmbus_get_adapter(). We can handle that by simply doing > the dual mode adapter type check before calling > intel_gmbus_get_adapter(). > Ref: https://patchwork.freedesktop.org/series/96433/ > > [Test] > 1. install kernel > 2. reboot > 3. check the monitor works well. > > [Regression Potential] > low, the patches has been landed on mainline and linux-next Applied to jammy:linux. Thanks, -Andrea PS sorry, ignore the previous mail, I responded to the individual patches...
BugLink: https://bugs.launchpad.net/bugs/1949321 [Impact] System hangs on black screen when reboot [Fix] Looks like our VBIOS/GOP generally fail to turn the DP dual mode adater TMDS output buffers back on after a reboot. This leads to a black screen after reboot if we turned the TMDS output buffers off prior to reboot. And if i915 decides to do a fastboot the black screen will persist even after i915 takes over. Apparently this has been a problem ever since commit b2ccb822d376 ("drm/i915:Enable/disable TMDS output buffers in DP++ adaptor as needed") if one rebooted while the display was turned off. And things became worse with commit fe0f1e3bfdfe ("drm/i915: Shut down displays gracefully on reboot") since now we always turn the display off before a reboot. This was reported on a RKL, but I confirmed the same behaviour on my SNB as well. So looks pretty universal. Let's fix this by explicitly turning the TMDS output buffers back on in the encoder->shutdown() hook. Note that this gets called after irqs have been disabled, so the i2c communication with the DP dual mode adapter has to be performed via polling (which the gmbus code is perfectly happy to do for us). We also need a bit of care in handling DDI encoders which may or may not be set up for HDMI output. Specifically ddc_pin will not be populated for a DP only DDI encoder, in which case we don't want to call intel_gmbus_get_adapter(). We can handle that by simply doing the dual mode adapter type check before calling intel_gmbus_get_adapter(). Ref: https://patchwork.freedesktop.org/series/96433/ [Test] 1. install kernel 2. reboot 3. check the monitor works well. [Regression Potential] low, the patches has been landed on mainline and linux-next V2: reSRU the formal patches for Jammy Jani Nikula (1): drm/i915/hdmi: convert intel_hdmi_to_dev to intel_hdmi_to_i915 Paolo Pisati (1): UBUNTU: Ubuntu-unstable-5.15.0-9.9 Ville Syrjälä (2): drm/i915: Don't request GMBUS to generate irqs when called while irqs are off drm/i915/hdmi: Turn DP++ TMDS output buffers back on in encoder->shutdown() debian.master/changelog | 17 ++++++++---- debian.master/reconstruct | 3 +- drivers/gpu/drm/i915/display/g4x_hdmi.c | 1 + drivers/gpu/drm/i915/display/intel_ddi.c | 1 + drivers/gpu/drm/i915/display/intel_gmbus.c | 13 +++++++-- drivers/gpu/drm/i915/display/intel_hdmi.c | 32 ++++++++++++++-------- drivers/gpu/drm/i915/display/intel_hdmi.h | 1 + 7 files changed, 49 insertions(+), 19 deletions(-)