From: Hans de Goede hdegoede@redhat.com
commit aee6f25e9c911323aa89a200e1bb160c1613ed3d upstream.
After the recently added commit fe0f1e3bfdfe ("drm/i915: Shut down displays gracefully on reboot"), the DSI panel on a Cherry Trail based Predia Basic tablet would no longer properly light up after reboot.
I've managed to reproduce this without rebooting by doing: chvt 3; echo 1 > /sys/class/graphics/fb0/blank;\ echo 0 > /sys/class/graphics/fb0/blank
Which rapidly turns the panel off and back on again.
The vlv_dsi.c code uses an intel_dsi_msleep() helper for the various delays used for panel on/off, since starting with MIPI-sequences version >= 3 the delays are already included inside the MIPI-sequences.
The problems exposed by the "Shut down displays gracefully on reboot" change, show that using this helper for the panel_pwr_cycle_delay is not the right thing to do. This has not been noticed until now because normally the panel never is cycled off and directly on again in quick succession.
Change the msleep for the panel_pwr_cycle_delay to a normal msleep() call to avoid the panel staying black after a quick off + on cycle.
Cc: Ville Syrjälä ville.syrjala@linux.intel.com Fixes: fe0f1e3bfdfe ("drm/i915: Shut down displays gracefully on reboot") Signed-off-by: Hans de Goede hdegoede@redhat.com Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20210325114823.44922-1-hdegoed... (cherry picked from commit 2878b29fc25a0dac0e1c6c94177f07c7f94240f0) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/i915/display/vlv_dsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/display/vlv_dsi.c +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c @@ -992,14 +992,14 @@ static void intel_dsi_post_disable(struc * FIXME As we do with eDP, just make a note of the time here * and perform the wait before the next panel power on. */ - intel_dsi_msleep(intel_dsi, intel_dsi->panel_pwr_cycle_delay); + msleep(intel_dsi->panel_pwr_cycle_delay); }
static void intel_dsi_shutdown(struct intel_encoder *encoder) { struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
- intel_dsi_msleep(intel_dsi, intel_dsi->panel_pwr_cycle_delay); + msleep(intel_dsi->panel_pwr_cycle_delay); }
static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,