From: Jitao Shi <jitao.shi@xxxxxxxxxxxx> [ Upstream commit cde7e2e35c2866d22a3a012e72a41052dfcc255d ] In order to match the changes of "Use the drm_panel_bridge API", the poweron/poweroff of dsi is extracted from enable/disable and defined as new funcs (atomic_pre_enable/atomic_post_disable). Since dsi_poweron is moved from dsi_enable to pre_enable function, in order to avoid poweron failure, the operation of dsi register fails to cause bus hang. Therefore, the protection mechanism is added to the dsi_enable function. Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge API") Link: https://patchwork.kernel.org/project/linux-mediatek/patch/1653012007-11854-3-git-send-email-xinlei.lee@xxxxxxxxxxxx/ Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx> Signed-off-by: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> Reviewed-by: Rex-BC Chen <rex-bc.chen@xxxxxxxxxxxx> Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/mediatek/mtk_dsi.c | 53 +++++++++++++++++++----------- 1 file changed, 34 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 2c09b43705ef..1b13e429e9d9 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -674,16 +674,6 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) if (--dsi->refcount != 0) return; - /* - * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since - * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(), - * which needs irq for vblank, and mtk_dsi_stop() will disable irq. - * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(), - * after dsi is fully set. - */ - mtk_dsi_stop(dsi); - - mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500); mtk_dsi_reset_engine(dsi); mtk_dsi_lane0_ulp_mode_enter(dsi); mtk_dsi_clk_ulp_mode_enter(dsi); @@ -698,17 +688,9 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) static void mtk_output_dsi_enable(struct mtk_dsi *dsi) { - int ret; - if (dsi->enabled) return; - ret = mtk_dsi_poweron(dsi); - if (ret < 0) { - DRM_ERROR("failed to power on dsi\n"); - return; - } - mtk_dsi_set_mode(dsi); mtk_dsi_clk_hs_mode(dsi, 1); @@ -722,7 +704,16 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi) if (!dsi->enabled) return; - mtk_dsi_poweroff(dsi); + /* + * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since + * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(), + * which needs irq for vblank, and mtk_dsi_stop() will disable irq. + * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(), + * after dsi is fully set. + */ + mtk_dsi_stop(dsi); + + mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500); dsi->enabled = false; } @@ -759,13 +750,37 @@ static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge, { struct mtk_dsi *dsi = bridge_to_dsi(bridge); + if (dsi->refcount == 0) + return; + mtk_output_dsi_enable(dsi); } +static void mtk_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) +{ + struct mtk_dsi *dsi = bridge_to_dsi(bridge); + int ret; + + ret = mtk_dsi_poweron(dsi); + if (ret < 0) + DRM_ERROR("failed to power on dsi\n"); +} + +static void mtk_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) +{ + struct mtk_dsi *dsi = bridge_to_dsi(bridge); + + mtk_dsi_poweroff(dsi); +} + static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = { .attach = mtk_dsi_bridge_attach, .atomic_disable = mtk_dsi_bridge_atomic_disable, .atomic_enable = mtk_dsi_bridge_atomic_enable, + .atomic_pre_enable = mtk_dsi_bridge_atomic_pre_enable, + .atomic_post_disable = mtk_dsi_bridge_atomic_post_disable, .mode_set = mtk_dsi_bridge_mode_set, }; -- 2.35.1