SST with 128b/132b channel coding needs this too. Extract to a separate
helper, independent of MST.
Pass timeout in as a parameter, anticipating that we can reduce the
timeout for SST.
v2: Clean up kernel-doc a bit
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
drivers/gpu/drm/display/drm_dp_helper.c | 54 ++++++++++++++++++-
drivers/gpu/drm/display/drm_dp_mst_topology.c | 36 +------------
include/drm/display/drm_dp_helper.h | 2 +
3 files changed, 57 insertions(+), 35 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 6ee51003de3c..fdb55c462d64 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -22,15 +22,16 @@
#include <linux/backlight.h>
#include <linux/delay.h>
+#include <linux/dynamic_debug.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/init.h>
+#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/string_helpers.h>
-#include <linux/dynamic_debug.h>
#include <drm/display/drm_dp_helper.h>
#include <drm/display/drm_dp_mst_helper.h>
@@ -779,6 +780,57 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
}
EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status);
+static int read_payload_update_status(struct drm_dp_aux *aux)
+{
+ int ret;
+ u8 status;
+
+ ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
+ if (ret < 0)
+ return ret;
+
+ return status;
+}
+
+/**
+ * drm_dp_dpcd_poll_act_handled() - Poll for ACT handled status
+ * @aux: DisplayPort AUX channel
+ * @timeout_ms: Timeout in ms
+ *
+ * Try waiting for the sink to finish updating its payload table by polling for
+ * the ACT handled bit of DP_PAYLOAD_TABLE_UPDATE_STATUS for up to @timeout_ms
+ * milliseconds, defaulting to 3000 ms if 0.
+ *
+ * Returns:
+ * 0 if the ACT was handled in time, negative error code on failure.
+ */
+int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms)
+{
+ int ret, status;
+
+ /* default to 3 seconds, this is arbitrary */
+ timeout_ms = timeout_ms ?: 3000;
+
+ ret = readx_poll_timeout(read_payload_update_status, aux, status,
+ status & DP_PAYLOAD_ACT_HANDLED || status < 0,
+ 200, timeout_ms * USEC_PER_MSEC);
+ if (ret < 0 && status >= 0) {
+ drm_err(aux->drm_dev, "Failed to get ACT after %d ms, last status: %02x\n",
+ timeout_ms, status);
+ return -EINVAL;
+ } else if (status < 0) {
+ /*
+ * Failure here isn't unexpected - the hub may have
+ * just been unplugged
+ */
+ drm_dbg_kms(aux->drm_dev, "Failed to read payload table status: %d\n", status);
+ return status;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_dp_dpcd_poll_act_handled);
+
static bool is_edid_digital_input_dp(const struct drm_edid *drm_edid)
{
/* FIXME: get rid of drm_edid_raw() */
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index e6ee180815b2..32481628fa89 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -29,7 +29,6 @@
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
-#include <linux/iopoll.h>
#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
#include <linux/stacktrace.h>
@@ -4726,18 +4725,6 @@ static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
return ret;
}
-static int do_get_act_status(struct drm_dp_aux *aux)
-{
- int ret;
- u8 status;
-
- ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
- if (ret < 0)
- return ret;
-
- return status;
-}
-
/**
* drm_dp_check_act_status() - Polls for ACT handled status.
* @mgr: manager to use
@@ -4755,28 +4742,9 @@ int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
* There doesn't seem to be any recommended retry count or timeout in
* the MST specification. Since some hubs have been observed to take
* over 1 second to update their payload allocations under certain
- * conditions, we use a rather large timeout value.
+ * conditions, we use a rather large timeout value of 3 seconds.
*/
- const int timeout_ms = 3000;
- int ret, status;
-
- ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
- status & DP_PAYLOAD_ACT_HANDLED || status < 0,
- 200, timeout_ms * USEC_PER_MSEC);
- if (ret < 0 && status >= 0) {
- drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n",
- timeout_ms, status);
- return -EINVAL;
- } else if (status < 0) {
- /*
- * Failure here isn't unexpected - the hub may have
- * just been unplugged
- */
- drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status);
- return status;
- }
-
- return 0;
+ return drm_dp_dpcd_poll_act_handled(mgr->aux, 3000);
}
EXPORT_SYMBOL(drm_dp_check_act_status);
diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h
index 279624833ea9..38eea21d1082 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -567,6 +567,8 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
enum drm_dp_phy dp_phy,
u8 link_status[DP_LINK_STATUS_SIZE]);
+int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms);
+
bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
u8 real_edid_checksum);
--
2.39.5
