Panel drivers can send DSI commands in panel's prepare(), which happens before the bridge's enable() is called. The OMAP DSI driver currently only sets up the DSI interface at bridge's enable(), so prepare() cannot be used to send DSI commands.
This patch fixes the issue by making it possible to enable the DSI interface any time a command is about to be sent. Disabling the interface is be done via delayed work.
Clarifications for the delayed disable work and the panel doing DSI transactions:
bridge_enable: If the disable callback is called just before bridge_enable takes the dsi_bus_lock, no problem, bridge_enable just enables the interface again. If the callback is ran just after bridge_enable's dsi_bus_unlock, no problem, dsi->video_enabled == true so the callback does nothing.
bridge_disable: similar to bridge-enable, the callback won't do anything if video_enabled == true, and after bridge-disable has turned the video and the interface off, there's nothing to do for the callback.
omap_dsi_host_detach: this is called when the panel does mipi_dsi_detach(), and we expect the panel to _not_ do any DSI transactions after (or during) mipi_dsi_detatch(), so there are no race conditions.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Reviewed-by: Sebastian Reichel sebastian.reichel@collabora.com --- drivers/gpu/drm/omapdrm/dss/dsi.c | 50 +++++++++++++++++++++++++++---- drivers/gpu/drm/omapdrm/dss/dsi.h | 3 ++ 2 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c index 0dd5c0381080..8e11612f5fe1 100644 --- a/drivers/gpu/drm/omapdrm/dss/dsi.c +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c @@ -3500,6 +3500,9 @@ static void dsi_enable(struct dsi_data *dsi)
WARN_ON(!dsi_bus_is_locked(dsi));
+ if (WARN_ON(dsi->iface_enabled)) + return; + mutex_lock(&dsi->lock);
r = dsi_runtime_get(dsi); @@ -3512,6 +3515,8 @@ static void dsi_enable(struct dsi_data *dsi) if (r) goto err_init_dsi;
+ dsi->iface_enabled = true; + mutex_unlock(&dsi->lock);
return; @@ -3527,6 +3532,9 @@ static void dsi_disable(struct dsi_data *dsi) { WARN_ON(!dsi_bus_is_locked(dsi));
+ if (WARN_ON(!dsi->iface_enabled)) + return; + mutex_lock(&dsi->lock);
dsi_sync_vc(dsi, 0); @@ -3538,6 +3546,8 @@ static void dsi_disable(struct dsi_data *dsi)
dsi_runtime_put(dsi);
+ dsi->iface_enabled = false; + mutex_unlock(&dsi->lock); }
@@ -4226,10 +4236,12 @@ static ssize_t omap_dsi_host_transfer(struct mipi_dsi_host *host,
dsi_bus_lock(dsi);
- if (dsi->video_enabled) - r = _omap_dsi_host_transfer(dsi, vc, msg); - else - r = -EIO; + if (!dsi->iface_enabled) { + dsi_enable(dsi); + schedule_delayed_work(&dsi->dsi_disable_work, msecs_to_jiffies(2000)); + } + + r = _omap_dsi_host_transfer(dsi, vc, msg);
dsi_bus_unlock(dsi);
@@ -4394,6 +4406,15 @@ static int omap_dsi_host_detach(struct mipi_dsi_host *host, if (WARN_ON(dsi->dsidev != client)) return -EINVAL;
+ cancel_delayed_work_sync(&dsi->dsi_disable_work); + + dsi_bus_lock(dsi); + + if (dsi->iface_enabled) + dsi_disable(dsi); + + dsi_bus_unlock(dsi); + omap_dsi_unregister_te_irq(dsi); dsi->dsidev = NULL; return 0; @@ -4629,9 +4650,12 @@ static void dsi_bridge_enable(struct drm_bridge *bridge) struct dsi_data *dsi = drm_bridge_to_dsi(bridge); struct omap_dss_device *dssdev = &dsi->output;
+ cancel_delayed_work_sync(&dsi->dsi_disable_work); + dsi_bus_lock(dsi);
- dsi_enable(dsi); + if (!dsi->iface_enabled) + dsi_enable(dsi);
dsi_enable_video_output(dssdev, VC_VIDEO);
@@ -4645,6 +4669,8 @@ static void dsi_bridge_disable(struct drm_bridge *bridge) struct dsi_data *dsi = drm_bridge_to_dsi(bridge); struct omap_dss_device *dssdev = &dsi->output;
+ cancel_delayed_work_sync(&dsi->dsi_disable_work); + dsi_bus_lock(dsi);
dsi->video_enabled = false; @@ -4837,6 +4863,18 @@ static const struct soc_device_attribute dsi_soc_devices[] = { { /* sentinel */ } };
+static void omap_dsi_disable_work_callback(struct work_struct *work) +{ + struct dsi_data *dsi = container_of(work, struct dsi_data, dsi_disable_work.work); + + dsi_bus_lock(dsi); + + if (dsi->iface_enabled && !dsi->video_enabled) + dsi_disable(dsi); + + dsi_bus_unlock(dsi); +} + static int dsi_probe(struct platform_device *pdev) { const struct soc_device_attribute *soc; @@ -4870,6 +4908,8 @@ static int dsi_probe(struct platform_device *pdev) INIT_DEFERRABLE_WORK(&dsi->framedone_timeout_work, dsi_framedone_timeout_work_callback);
+ INIT_DEFERRABLE_WORK(&dsi->dsi_disable_work, omap_dsi_disable_work_callback); + #ifdef DSI_CATCH_MISSING_TE timer_setup(&dsi->te_timer, dsi_te_timeout, 0); #endif diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.h b/drivers/gpu/drm/omapdrm/dss/dsi.h index de9411067ba2..601707c0ecc4 100644 --- a/drivers/gpu/drm/omapdrm/dss/dsi.h +++ b/drivers/gpu/drm/omapdrm/dss/dsi.h @@ -394,6 +394,7 @@ struct dsi_data { atomic_t do_ext_te_update;
bool te_enabled; + bool iface_enabled; bool video_enabled;
struct delayed_work framedone_timeout_work; @@ -443,6 +444,8 @@ struct dsi_data {
struct omap_dss_device output; struct drm_bridge bridge; + + struct delayed_work dsi_disable_work; };
struct dsi_packet_sent_handler_data {