diff options
| author | Imre Deak <[email protected]> | 2024-01-04 10:30:07 +0200 |
|---|---|---|
| committer | Imre Deak <[email protected]> | 2024-01-08 18:57:21 +0200 |
| commit | 2e4b90fbe75536c978218bb3eb1d04f8988e13cd (patch) | |
| tree | 69cc82d683abf6292dc96c8fbd8daca17cc72e78 | |
| parent | 9210e94a5a3bf7fc84b3d94dd5d2099ca434931b (diff) | |
drm/i915: Filter out glitches on HPD lines during hotplug detection
Glitches deasserting the connector HPD line can lead to incorrectly
detecting a disconnect event (a glitch asserting the line will only
cause a redundant connect->disconnect transition). The source of such a
glitch can be noise on the line or a 0.5ms-1ms MST IRQ_HPD pulse. TypeC
ports in the DP-alt or TBT-alt mode filter out these glitches inernally,
but for others the driver has to do this. Make it so by polling the HPD
line on these connectors for 4 ms.
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Jouni Högander <[email protected]>
Signed-off-by: Imre Deak <[email protected]>
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp.c | 13 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_tc.c | 9 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_tc.h | 1 |
3 files changed, 21 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index a320bb0292d9..93f9985ef75c 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -5460,11 +5460,20 @@ bool intel_digital_port_connected_locked(struct intel_encoder *encoder) { struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); struct intel_digital_port *dig_port = enc_to_dig_port(encoder); + bool is_glitch_free = intel_tc_port_handles_hpd_glitches(dig_port); bool is_connected = false; intel_wakeref_t wakeref; - with_intel_display_power(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref) - is_connected = dig_port->connected(encoder); + with_intel_display_power(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref) { + unsigned long wait_expires = jiffies + msecs_to_jiffies_timeout(4); + + do { + is_connected = dig_port->connected(encoder); + if (is_connected || is_glitch_free) + break; + usleep_range(10, 30); + } while (time_before(jiffies, wait_expires)); + } return is_connected; } diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c index 80aed9e87927..f34743e6eeed 100644 --- a/drivers/gpu/drm/i915/display/intel_tc.c +++ b/drivers/gpu/drm/i915/display/intel_tc.c @@ -122,6 +122,15 @@ bool intel_tc_port_in_legacy_mode(struct intel_digital_port *dig_port) return intel_tc_port_in_mode(dig_port, TC_PORT_LEGACY); } +bool intel_tc_port_handles_hpd_glitches(struct intel_digital_port *dig_port) +{ + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); + enum phy phy = intel_port_to_phy(i915, dig_port->base.port); + struct intel_tc_port *tc = to_tc_port(dig_port); + + return intel_phy_is_tc(i915, phy) && !tc->legacy_port; +} + /* * The display power domains used for TC ports depending on the * platform and TC mode (legacy, DP-alt, TBT): diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h index 936fa2daaa74..26c4265368c1 100644 --- a/drivers/gpu/drm/i915/display/intel_tc.h +++ b/drivers/gpu/drm/i915/display/intel_tc.h @@ -15,6 +15,7 @@ struct intel_encoder; bool intel_tc_port_in_tbt_alt_mode(struct intel_digital_port *dig_port); bool intel_tc_port_in_dp_alt_mode(struct intel_digital_port *dig_port); bool intel_tc_port_in_legacy_mode(struct intel_digital_port *dig_port); +bool intel_tc_port_handles_hpd_glitches(struct intel_digital_port *dig_port); bool intel_tc_port_connected(struct intel_encoder *encoder); |