Hi, On Fri, Jul 9, 2021 at 1:41 PM Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > On Fri, Jul 09, 2021 at 06:54:05AM -0700, Doug Anderson wrote: > > Hi, > > > > On Sat, Jun 26, 2021 at 9:52 AM Rajeev Nandan <rajeevny@xxxxxxxxxxxxxx> wrote: > > > > > > This series adds the support for the eDP panel that needs the backlight > > > controlling over the DP AUX channel using DPCD registers of the panel > > > as per the VESA's standard. > > > > > > This series also adds support for the Samsung eDP AMOLED panel that > > > needs DP AUX to control the backlight, and introduces new delays in the > > > @panel_desc.delay to support this panel. > > > > > > This patch series depends on the following two series: > > > - Doug's series [1], exposed the DP AUX channel to the panel-simple. > > > - Lyude's series [2], introduced new drm helper functions for DPCD > > > backlight. > > > > > > This series is the logical successor to the series [3]. > > > > > > Changes in v1: > > > - Created dpcd backlight helper with very basic functionality, added > > > backlight registration in the ti-sn65dsi86 bridge driver. > > > > > > Changes in v2: > > > - Created a new DisplayPort aux backlight driver and moved the code from > > > drm_dp_aux_backlight.c (v1) to the new driver. > > > > > > Changes in v3: > > > - Fixed module compilation (kernel test bot). > > > > > > Changes in v4: > > > - Added basic DPCD backlight support in panel-simple. > > > - Added support for a new Samsung panel ATNA33XC20 that needs DPCD > > > backlight controlling and has a requirement of delays between enable > > > GPIO and regulator. > > > > > > Changes in v5: > > > Addressed review suggestions from Douglas: > > > - Created a new API drm_panel_dp_aux_backlight() in drm_panel.c > > > - Moved DP AUX backlight functions from panel-simple.c to drm_panel.c > > > - panel-simple probe() calls drm_panel_dp_aux_backlight() to create > > > backlight when the backlight phandle is not specified in panel DT > > > and DP AUX channel is present. > > > - Added check for drm_edp_backlight_supported() before registering. > > > - Removed the @uses_dpcd_backlight flag from panel_desc as this > > > should be auto-detected. > > > - Updated comments/descriptions. > > > > > > Changes in v6: > > > - Rebased > > > - Updated wanrning messages, fixed word wrapping in comments. > > > - Fixed ordering of memory allocation > > > > > > Changes in v7: > > > - Updated the disable_to_power_off and power_to_enable panel delays > > > as discovered at <https://crrev.com/c/2966167> (Douglas) > > > > > > Changes in v8: > > > - Now using backlight_is_blank() to get the backlight blank status (Sam Ravnborg) > > > - Added a new patch #4 to fix the warnings for eDP panel description (Sam Ravnborg) > > > > > > [1] https://lore.kernel.org/dri-devel/20210525000159.3384921-1-dianders@xxxxxxxxxxxx/ > > > [2] https://lore.kernel.org/dri-devel/20210514181504.565252-1-lyude@xxxxxxxxxx/ > > > [3] https://lore.kernel.org/dri-devel/1619416756-3533-1-git-send-email-rajeevny@xxxxxxxxxxxxxx/ > > > > > > Rajeev Nandan (6): > > > drm/panel: add basic DP AUX backlight support > > > drm/panel-simple: Support DP AUX backlight > > > drm/panel-simple: Support for delays between GPIO & regulator > > > drm/panel-simple: Update validation warnings for eDP panel description > > > dt-bindings: display: simple: Add Samsung ATNA33XC20 > > > drm/panel-simple: Add Samsung ATNA33XC20 > > > > > > .../bindings/display/panel/panel-simple.yaml | 2 + > > > drivers/gpu/drm/drm_panel.c | 108 +++++++++++++++++++++ > > > drivers/gpu/drm/panel/panel-simple.c | 73 +++++++++++++- > > > include/drm/drm_panel.h | 15 ++- > > > 4 files changed, 190 insertions(+), 8 deletions(-) > > > > Pushed to drm-misc-next. > > > > 4bfe6c8f7c23 drm/panel-simple: Add Samsung ATNA33XC20 > > c20dec193584 dt-bindings: display: simple: Add Samsung ATNA33XC20 > > 13aceea56fd5 drm/panel-simple: Update validation warnings for eDP > > panel description > > 18a1488bf1e1 drm/panel-simple: Support for delays between GPIO & regulator > > bfd451403d70 drm/panel-simple: Support DP AUX backlight > > 10f7b40e4f30 drm/panel: add basic DP AUX backlight support > > depmod: ERROR: Cycle detected: drm_kms_helper -> drm -> drm_kms_helper > > Looks to be due to drm_edp_backlight_enable(). Ugh. Thanks for the report! I've taken a schwag at a fix here: https://lore.kernel.org/lkml/20210709152909.1.I23eb4cc5a680341e7b3e791632a635566fa5806a@changeid/ -Doug