summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/display
diff options
context:
space:
mode:
authorDave Airlie <airlied@redhat.com>2025-06-23 10:49:25 +1000
committerDave Airlie <airlied@redhat.com>2025-06-23 10:49:27 +1000
commit36c52fb703e90388285963fc8f03cf60f76cbe4c (patch)
treead4ac082742408d54a7a165d9fb006d06f8d064a /drivers/gpu/drm/display
parent9356b50af547e872d9191754c72c83ff6be3b97c (diff)
parentb2f7e30d2e4a34fcee8111d713bef4f29dc23c77 (diff)
Merge tag 'drm-intel-next-2025-06-18' of https://gitlab.freedesktop.org/drm/i915/kernel into drm-next
drm/i915 feature pull for v6.17: Features and functionality: - Add support for DSC fractional link bpp on DP MST (Imre) - Add support for simultaneous Panel Replay and Adaptive Sync (Jouni) - Add support for PTL+ double buffered LUT registers (Chaitanya, Ville) - Add PIPEDMC event handling in preparation for flip queue (Ville) Refactoring and cleanups: - Rename lots of DPLL interfaces to unify them (Suraj) - Allocate struct intel_display dynamically (Jani) - Abstract VLV IOSF sideband better (Jani) - Use str_true_false() helper (Yumeng Fang) - Refactor DSB code in preparation for flip queue (Ville) - Use drm_modeset_lock_assert_held() instead of open coding (Luca) - Remove unused arg from skl_scaler_get_filter_select() (Luca) - Split out a separate display register header (Jani) - Abstract DRAM detection better (Jani) - Convert LPT/WPT SBI sideband to struct intel_display (Jani) Fixes: - Fix DSI HS command dispatch with forced pipeline flush (Gareth Yu) - Fix BMG and LNL+ DP adaptive sync SDP programming (Ankit) - Fix error path for xe display workqueue allocation (Haoxiang Li) - Disable DP AUX access probe where not required (Imre) - Fix DKL PHY access if the port is invalid (Luca) - Fix PSR2_SU_STATUS access on ADL+ (Jouni) - Add sanity checks for porch and sync on BXT/GLK DSI (Ville) DRM core changes: - Change AUX DPCD access probe address (Imre) - Refactor EDID quirks, amd make them available to drivers (Imre) - Add quirk for DPCD access probe (Imre) - Add DPCD definitions for Panel Replay capabilities (Jouni) Merges: - Backmerges to sync with v6.15-rcs and v6.16-rc1 (Jani) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Jani Nikula <jani.nikula@intel.com> Link: https://lore.kernel.org/r/fff9f231850ed410bd81b53de43eff0b98240d31@intel.com
Diffstat (limited to 'drivers/gpu/drm/display')
-rw-r--r--drivers/gpu/drm/display/drm_dp_helper.c44
1 files changed, 30 insertions, 14 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 896bba2adb3b..385a1bfdb272 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -693,6 +693,34 @@ void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered)
EXPORT_SYMBOL(drm_dp_dpcd_set_powered);
/**
+ * drm_dp_dpcd_set_probe() - Set whether a probing before DPCD access is done
+ * @aux: DisplayPort AUX channel
+ * @enable: Enable the probing if required
+ */
+void drm_dp_dpcd_set_probe(struct drm_dp_aux *aux, bool enable)
+{
+ WRITE_ONCE(aux->dpcd_probe_disabled, !enable);
+}
+EXPORT_SYMBOL(drm_dp_dpcd_set_probe);
+
+static bool dpcd_access_needs_probe(struct drm_dp_aux *aux)
+{
+ /*
+ * HP ZR24w corrupts the first DPCD access after entering power save
+ * mode. Eg. on a read, the entire buffer will be filled with the same
+ * byte. Do a throw away read to avoid corrupting anything we care
+ * about. Afterwards things will work correctly until the monitor
+ * gets woken up and subsequently re-enters power save mode.
+ *
+ * The user pressing any button on the monitor is enough to wake it
+ * up, so there is no particularly good place to do the workaround.
+ * We just have to do it before any DPCD access and hope that the
+ * monitor doesn't power down exactly after the throw away read.
+ */
+ return !aux->is_remote && !READ_ONCE(aux->dpcd_probe_disabled);
+}
+
+/**
* drm_dp_dpcd_read() - read a series of bytes from the DPCD
* @aux: DisplayPort AUX channel (SST or MST)
* @offset: address of the (first) register to read
@@ -713,20 +741,8 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
{
int ret;
- /*
- * HP ZR24w corrupts the first DPCD access after entering power save
- * mode. Eg. on a read, the entire buffer will be filled with the same
- * byte. Do a throw away read to avoid corrupting anything we care
- * about. Afterwards things will work correctly until the monitor
- * gets woken up and subsequently re-enters power save mode.
- *
- * The user pressing any button on the monitor is enough to wake it
- * up, so there is no particularly good place to do the workaround.
- * We just have to do it before any DPCD access and hope that the
- * monitor doesn't power down exactly after the throw away read.
- */
- if (!aux->is_remote) {
- ret = drm_dp_dpcd_probe(aux, DP_DPCD_REV);
+ if (dpcd_access_needs_probe(aux)) {
+ ret = drm_dp_dpcd_probe(aux, DP_LANE0_1_STATUS);
if (ret < 0)
return ret;
}