summaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
authorLyude Paul <lyude@redhat.com>2024-04-05 01:35:53 +0200
committerLyude Paul <lyude@redhat.com>2024-04-10 20:17:51 +0200
commit9c8a10bf1f3467b2c16f6848249bdc7692ace825 (patch)
treefdfe06f574b8397eec7cf5f628f8557a563a446d /drivers
parentdrm/bridge: imx8mp-hdmi-tx: Convert to platform remove callback returning void (diff)
downloadlinux-9c8a10bf1f3467b2c16f6848249bdc7692ace825.tar.xz
linux-9c8a10bf1f3467b2c16f6848249bdc7692ace825.zip
drm/nouveau/kms/nv50-: Disable AUX bus for disconnected DP ports
GSP has its own state for keeping track of whether or not a given display connector is plugged in or not, and enforces this state on the driver. In particular, AUX transactions on a DisplayPort connector which GSP says is disconnected can never succeed - and can in some cases even cause unexpected timeouts, which can trickle up to cause other problems. A good example of this is runtime power management: where we can actually get stuck trying to resume the GPU if a userspace application like fwupd tries accessing a drm_aux_dev for a disconnected port. This was an issue I hit a few times with my Slimbook Executive 16 - where trying to offload something to the discrete GPU would wake it up, and then potentially cause it to timeout as fwupd tried to immediately access the dp_aux_dev nodes for nouveau. Likewise: we don't really have any cases I know of where we'd want to ignore this state and try an aux transaction anyway - and failing pointless aux transactions immediately can even speed things up. So - let's start enabling/disabling the aux bus in nouveau_dp_detect() to fix this. We enable the aux bus during connector probing, and leave it enabled if we discover something is actually on the connector. Otherwise, we just shut it off. This should fix some people's runtime PM issues (like myself), and also get rid of quite of a lot of GSP error spam in dmesg. Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Dave Airlie <airlied@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240404233736.7946-2-lyude@redhat.com
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_dp.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index 7de7707ec6a8..3f6ccce20ea0 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -232,6 +232,9 @@ nouveau_dp_detect(struct nouveau_connector *nv_connector,
dpcd[DP_DPCD_REV] != 0)
return NOUVEAU_DP_SST;
+ // Ensure that the aux bus is enabled for probing
+ drm_dp_dpcd_set_powered(&nv_connector->aux, true);
+
mutex_lock(&nv_encoder->dp.hpd_irq_lock);
if (mstm) {
/* If we're not ready to handle MST state changes yet, just
@@ -293,6 +296,13 @@ out:
if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
nv50_mstm_remove(mstm);
+ /* GSP doesn't like when we try to do aux transactions on a port it considers disconnected,
+ * and since we don't really have a usecase for that anyway - just disable the aux bus here
+ * if we've decided the connector is disconnected
+ */
+ if (ret == NOUVEAU_DP_NONE)
+ drm_dp_dpcd_set_powered(&nv_connector->aux, false);
+
mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
return ret;
}