On AUX transfer timeout, as per DP spec need to retry for 3 times and
has to be restarted freshly.
v3: handle timeout and dont rely on register value on timeout (Imre)
Signed-off-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx>
---
.../drm/i915/display/intel_display_types.h | 1 -
drivers/gpu/drm/i915/display/intel_dp_aux.c | 72 +++++++++----------
2 files changed, 34 insertions(+), 39 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 2d8297f8d088..0942b109b4ca 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1741,7 +1741,6 @@ struct intel_dp {
/* sink or branch descriptor */
struct drm_dp_desc desc;
struct drm_dp_aux aux;
- u32 aux_busy_last_status;
u8 train_set[4];
struct intel_pps pps;
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
index 0c27db8ae4f1..244b4d7d716d 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
@@ -36,25 +36,24 @@ static void intel_dp_aux_unpack(u32 src, u8 *dst, int dst_bytes)
dst[i] = src >> ((3 - i) * 8);
}
-static u32
-intel_dp_aux_wait_done(struct intel_dp *intel_dp)
+static int
+intel_dp_aux_wait_done(struct intel_dp *intel_dp, u32 *status)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
const unsigned int timeout_ms = 10;
- u32 status;
int ret;
ret = __intel_de_wait_for_register(i915, ch_ctl,
DP_AUX_CH_CTL_SEND_BUSY, 0,
- 2, timeout_ms, &status);
+ 50, timeout_ms, status);
if (ret == -ETIMEDOUT)
drm_err(&i915->drm,
"%s: did not complete or timeout within %ums (status 0x%08x)\n",
- intel_dp->aux.name, timeout_ms, status);
+ intel_dp->aux.name, timeout_ms, *status);
- return status;
+ return ret;
}
static u32 g4x_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
@@ -186,10 +185,7 @@ static u32 skl_get_aux_send_ctl(struct intel_dp *intel_dp,
*/
ret = DP_AUX_CH_CTL_SEND_BUSY |
DP_AUX_CH_CTL_DONE |
- DP_AUX_CH_CTL_INTERRUPT |
- DP_AUX_CH_CTL_TIME_OUT_ERROR |
DP_AUX_CH_CTL_TIME_OUT_MAX |
- DP_AUX_CH_CTL_RECEIVE_ERROR |
DP_AUX_CH_CTL_MESSAGE_SIZE(send_bytes) |
DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(intel_dp_aux_fw_sync_len()) |
DP_AUX_CH_CTL_SYNC_PULSE_SKL(intel_dp_aux_sync_len());
@@ -273,30 +269,6 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
* it using the same AUX CH simultaneously
*/
- /* Try to wait for any previous AUX channel activity */
- for (try = 0; try < 3; try++) {
- status = intel_de_read_notrace(i915, ch_ctl);
- if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
- break;
- msleep(1);
- }
- /* just trace the final value */
- trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true);
-
- if (try == 3) {
- const u32 status = intel_de_read(i915, ch_ctl);
-
- if (status != intel_dp->aux_busy_last_status) {
- drm_WARN(&i915->drm, 1,
- "%s: not started (status 0x%08x)\n",
- intel_dp->aux.name, status);
- intel_dp->aux_busy_last_status = status;
- }
-
- ret = -EBUSY;
- goto out;
- }
-
/* Only 5 data registers! */
if (drm_WARN_ON(&i915->drm, send_bytes > 20 || recv_size > 20)) {
ret = -E2BIG;
@@ -304,14 +276,31 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
}
while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, clock++))) {
- u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
+ /* Must try at least 3 times according to DP spec */
+ for (try = 0; try < 5; try++) {
+ u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
send_bytes,
aux_clock_divider);
- send_ctl |= aux_send_ctl_flags;
+ send_ctl |= aux_send_ctl_flags;
+
+ /* Try to wait for any previous AUX channel activity */
+ /* TODO: if typeC then 4.2ms else 800us. For DG2 add 1.5ms for both cases */
+ ret = intel_dp_aux_wait_done(intel_dp, &status);
+ /* just trace the final value */
+ trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true);
+
+ /* On timeout dont read the status bits as its not updated */
+ if (ret == -ETIMEDOUT) {
+ drm_WARN(&i915->drm, 1,
+ "%s: not started, previous Tx still in process (status 0x%08x)\n",
+ intel_dp->aux.name, status);
+ if (try > 3)
+ goto out;
+ else
+ continue;
+ }
- /* Must try at least 3 times according to DP spec */
- for (try = 0; try < 5; try++) {
/* Load the send data into the aux channel data registers */
for (i = 0; i < send_bytes; i += 4)
intel_de_write(i915, ch_data[i >> 2],
@@ -320,8 +309,15 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
/* Send the command and wait for it to complete */
intel_de_write(i915, ch_ctl, send_ctl);
+ intel_de_rmw(i915, ch_ctl, DP_AUX_CH_CTL_INTERRUPT |
+ DP_AUX_CH_CTL_TIME_OUT_ERROR |
+ DP_AUX_CH_CTL_RECEIVE_ERROR, 0);
- status = intel_dp_aux_wait_done(intel_dp);
+ ret = intel_dp_aux_wait_done(intel_dp, &status);
+
+ /* On timeout dont read the status bits as its not updated */
+ if (ret == -ETIMEDOUT)
+ continue;
/* Clear done status and any errors */
intel_de_write(i915, ch_ctl,
--
2.25.1
