From 9e15123eca7942caa8a3e1f58ec0df7d088df149 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 31 Jan 2023 14:18:25 -0800 Subject: drm/msm/dsi: Stop unconditionally powering up DSI hosts at modeset In commit 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time"), we moved powering up DSI hosts to modeset time. This wasn't because it was an elegant design, but there were no better options. That commit actually ended up breaking ps8640, and thus was born commit ec7981e6c614 ("drm/msm/dsi: don't powerup at modeset time for parade-ps8640") as a temporary hack to un-break ps8640 by moving it to the old way of doing things. It turns out that ps8640 _really_ doesn't like its pre_enable() function to be called after dsi_mgr_bridge_power_on(). Specifically (from experimentation, not because I have any inside knowledge), it looks like the assertion of "RST#" in the ps8640 runtime resume handler seems like it's not allowed to happen after dsi_mgr_bridge_power_on() Recently, Dave Stevenson's series landed allowing bridges some control over pre_enable ordering. The meaty commit for our purposes is commit 4fb912e5e190 ("drm/bridge: Introduce pre_enable_prev_first to alter bridge init order"). As documented by that series, if a bridge doesn't set "pre_enable_prev_first" then we should use the old ordering. Now that we have the commit ("drm/bridge: tc358762: Set pre_enable_prev_first") we can go back to the old ordering, which also allows us to remove the ps8640 special case. One last note is that even without reverting commit 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time"), if you _just_ revert the ps8640 special case and try it out then it doesn't seem to fail anymore. I spent time bisecting / debugging this and it turns out to be mostly luck, so we still want this patch to make sure it's solid. Specifically the reason it sorta works these days is because we implemented wait_hpd_asserted() in ps8640 now, plus the magic of "pm_runtime" autosuspend. The fact that we have wait_hpd_asserted() implemented means that we actually power the bridge chip up just a wee bit earlier and then the bridge happens to stay on because of autosuspend and thus ends up powered before dsi_mgr_bridge_power_on(). Cc: Dave Stevenson Cc: Dmitry Baryshkov Cc: Abhinav Kumar Signed-off-by: Douglas Anderson Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/521058/ Link: https://lore.kernel.org/r/20230131141756.RFT.v2.2.I4cfeab9d0e07e98ead23dd0736ab4461e6c69002@changeid Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/msm/dsi/dsi_manager.c | 38 +---------------------------------- 1 file changed, 1 insertion(+), 37 deletions(-) (limited to 'drivers/gpu/drm/msm/dsi/dsi_manager.c') diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c index 1bbac72dad35..2197a54b9b96 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -34,32 +34,6 @@ static struct msm_dsi_manager msm_dsim_glb; #define IS_SYNC_NEEDED() (msm_dsim_glb.is_sync_needed) #define IS_MASTER_DSI_LINK(id) (msm_dsim_glb.master_dsi_link_id == id) -#ifdef CONFIG_OF -static bool dsi_mgr_power_on_early(struct drm_bridge *bridge) -{ - struct drm_bridge *next_bridge = drm_bridge_get_next_bridge(bridge); - - /* - * If the next bridge in the chain is the Parade ps8640 bridge chip - * then don't power on early since it seems to violate the expectations - * of the firmware that the bridge chip is running. - * - * NOTE: this is expected to be a temporary special case. It's expected - * that we'll eventually have a framework that allows the next level - * bridge to indicate whether it needs us to power on before it or - * after it. When that framework is in place then we'll use it and - * remove this special case. - */ - return !(next_bridge && next_bridge->of_node && - of_device_is_compatible(next_bridge->of_node, "parade,ps8640")); -} -#else -static inline bool dsi_mgr_power_on_early(struct drm_bridge *bridge) -{ - return true; -} -#endif - static inline struct msm_dsi *dsi_mgr_get_dsi(int id) { return msm_dsim_glb.dsi[id]; @@ -265,12 +239,6 @@ static void dsi_mgr_bridge_power_on(struct drm_bridge *bridge) int ret; DBG("id=%d", id); - if (!msm_dsi_device_connected(msm_dsi)) - return; - - /* Do nothing with the host if it is slave-DSI in case of bonded DSI */ - if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id)) - return; ret = dsi_mgr_phy_enable(id, phy_shared_timings); if (ret) @@ -327,8 +295,7 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge) if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id)) return; - if (!dsi_mgr_power_on_early(bridge)) - dsi_mgr_bridge_power_on(bridge); + dsi_mgr_bridge_power_on(bridge); ret = msm_dsi_host_enable(host); if (ret) { @@ -438,9 +405,6 @@ static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge, msm_dsi_host_set_display_mode(host, adjusted_mode); if (is_bonded_dsi && other_dsi) msm_dsi_host_set_display_mode(other_dsi->host, adjusted_mode); - - if (dsi_mgr_power_on_early(bridge)) - dsi_mgr_bridge_power_on(bridge); } static enum drm_mode_status dsi_mgr_bridge_mode_valid(struct drm_bridge *bridge, -- cgit v1.2.3 From d8dd416cb420163f9631a01ddcce78628a6a5962 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 31 Jan 2023 14:18:26 -0800 Subject: drm/msm/dsi: More properly handle errors in regards to dsi_mgr_bridge_power_on() In commit 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time") the error handling with regards to dsi_mgr_bridge_power_on() got a bit worse. Specifically if we failed to power the bridge on then nothing would really notice. The modeset function couldn't return an error and thus we'd blindly go forward and try to do the pre-enable. In commit ec7981e6c614 ("drm/msm/dsi: don't powerup at modeset time for parade-ps8640") we added a special case to move the powerup back to pre-enable time for ps8640. When we did that, we didn't try to recover the old/better error handling just for ps8640. In the patch ("drm/msm/dsi: Stop unconditionally powering up DSI hosts at modeset") we've now moved the powering up back to exclusively being during pre-enable. That means we can add the better error handling back in, so let's do it. To do so we'll add a new function dsi_mgr_bridge_power_off() that's matches how errors were handled prior to commit 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time"). NOTE: Now that we have dsi_mgr_bridge_power_off(), it feels as if we should be calling it in dsi_mgr_bridge_post_disable(). That would make some sense, but doing so would change the current behavior and thus should be a separate patch. Specifically: * dsi_mgr_bridge_post_disable() always calls dsi_mgr_phy_disable() even in the slave-DSI case of bonded DSI. We'd need to add special handling for this if it's truly needed. * dsi_mgr_bridge_post_disable() calls msm_dsi_phy_pll_save_state() midway through the poweroff. * dsi_mgr_bridge_post_disable() has a different order of some of the poweroffs / IRQ disables. For now we'll leave dsi_mgr_bridge_post_disable() alone. Signed-off-by: Douglas Anderson Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/521059/ Link: https://lore.kernel.org/r/20230131141756.RFT.v2.3.I3c87b53c4ab61a7d5e05f601a4eb44c7e3809a01@changeid Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/msm/dsi/dsi_manager.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) (limited to 'drivers/gpu/drm/msm/dsi/dsi_manager.c') diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c index 2197a54b9b96..28b8012a21f2 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -228,7 +228,7 @@ static void msm_dsi_manager_set_split_display(u8 id) } } -static void dsi_mgr_bridge_power_on(struct drm_bridge *bridge) +static int dsi_mgr_bridge_power_on(struct drm_bridge *bridge) { int id = dsi_mgr_bridge_get_id(bridge); struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id); @@ -268,14 +268,31 @@ static void dsi_mgr_bridge_power_on(struct drm_bridge *bridge) if (is_bonded_dsi && msm_dsi1) msm_dsi_host_enable_irq(msm_dsi1->host); - return; + return 0; host1_on_fail: msm_dsi_host_power_off(host); host_on_fail: dsi_mgr_phy_disable(id); phy_en_fail: - return; + return ret; +} + +static void dsi_mgr_bridge_power_off(struct drm_bridge *bridge) +{ + int id = dsi_mgr_bridge_get_id(bridge); + struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id); + struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1); + struct mipi_dsi_host *host = msm_dsi->host; + bool is_bonded_dsi = IS_BONDED_DSI(); + + msm_dsi_host_disable_irq(host); + if (is_bonded_dsi && msm_dsi1) { + msm_dsi_host_disable_irq(msm_dsi1->host); + msm_dsi_host_power_off(msm_dsi1->host); + } + msm_dsi_host_power_off(host); + dsi_mgr_phy_disable(id); } static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge) @@ -295,7 +312,11 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge) if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id)) return; - dsi_mgr_bridge_power_on(bridge); + ret = dsi_mgr_bridge_power_on(bridge); + if (ret) { + dev_err(&msm_dsi->pdev->dev, "Power on failed: %d\n", ret); + return; + } ret = msm_dsi_host_enable(host); if (ret) { @@ -316,8 +337,7 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge) host1_en_fail: msm_dsi_host_disable(host); host_en_fail: - - return; + dsi_mgr_bridge_power_off(bridge); } void msm_dsi_manager_tpg_enable(void) -- cgit v1.2.3