• Stephen Boyd's avatar
    drm/panel: boe-tv101wum-nl6: Ensure DSI writes succeed during disable · a3ee9e0b
    Stephen Boyd authored
    The unprepare sequence has started to fail after moving to panel bridge
    code in the msm drm driver (commit 007ac026 ("drm/msm/dsi: switch to
    DRM_PANEL_BRIDGE")). You'll see messages like this in the kernel logs:
    
       panel-boe-tv101wum-nl6 ae94000.dsi.0: failed to set panel off: -22
    
    This is because boe_panel_enter_sleep_mode() needs an operating DSI link
    to set the panel into sleep mode. Performing those writes in the
    unprepare phase of bridge ops is too late, because the link has already
    been torn down by the DSI controller in post_disable, i.e. the PHY has
    been disabled, etc. See dsi_mgr_bridge_post_disable() for more details
    on the DSI .
    
    Split the unprepare function into a disable part and an unprepare part.
    For now, just the DSI writes to enter sleep mode are put in the disable
    function. This fixes the panel off routine and keeps the panel happy.
    
    My Wormdingler has an integrated touchscreen that stops responding to
    touch if the panel is only half disabled too. This patch fixes it. And
    finally, this saves power when the screen is off because without this
    fix the regulators for the panel are left enabled when nothing is being
    displayed on the screen.
    
    Fixes: 007ac026 ("drm/msm/dsi: switch to DRM_PANEL_BRIDGE")
    Fixes: a869b9db ("drm/panel: support for boe tv101wum-nl6 wuxga dsi video mode panel")
    Cc: yangcong <yangcong5@huaqin.corp-partner.google.com>
    Cc: Douglas Anderson <dianders@chromium.org>
    Cc: Jitao Shi <jitao.shi@mediatek.com>
    Cc: Sam Ravnborg <sam@ravnborg.org>
    Cc: Rob Clark <robdclark@chromium.org>
    Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
    Signed-off-by: default avatarStephen Boyd <swboyd@chromium.org>
    Reviewed-by: default avatarDouglas Anderson <dianders@chromium.org>
    Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
    Link: https://patchwork.freedesktop.org/patch/msgid/20230106030108.2542081-1-swboyd@chromium.org
    (cherry picked from commit c913cd54)
    Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
    a3ee9e0b
panel-boe-tv101wum-nl6.c 43.2 KB