From: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
Unfortunately even the HPD based detection added in
commit cfe5bdfb27fa ("drm/i915: Check HPD live state during eDP probe")
fails to detect that the VBT's eDP/DDI-A is a ghost on
Asus B360M-A (CFL+CNP). On that board eDP/DDI-A has its HPD
asserted despite nothing being actually connected there :(
The straps/fuses also indicate that the eDP port is present.
So if one boots with a VGA monitor connected the eDP probe will
mistake the DP->VGA converter hooked to DDI-E for an eDP panel
on DDI-A.
As a last resort check what kind of DP device we've detected,
and if it looks like a DP->VGA converter then conclude that
the eDP port should be ignored.
Cc: stable(a)vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9636
Fixes: cfe5bdfb27fa ("drm/i915: Check HPD live state during eDP probe")
Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
---
drivers/gpu/drm/i915/display/intel_dp.c | 28 +++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 54bd0bffa9f0..14ee05fabd05 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -6277,8 +6277,7 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
* (eg. Acer Chromebook C710), so we'll check it only if multiple
* ports are attempting to use the same AUX CH, according to VBT.
*/
- if (intel_bios_dp_has_shared_aux_ch(encoder->devdata) &&
- !intel_digital_port_connected(encoder)) {
+ if (intel_bios_dp_has_shared_aux_ch(encoder->devdata)) {
/*
* If this fails, presume the DPCD answer came
* from some other port using the same AUX CH.
@@ -6286,10 +6285,27 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
* FIXME maybe cleaner to check this before the
* DPCD read? Would need sort out the VDD handling...
*/
- drm_info(&dev_priv->drm,
- "[ENCODER:%d:%s] HPD is down, disabling eDP\n",
- encoder->base.base.id, encoder->base.name);
- goto out_vdd_off;
+ if (!intel_digital_port_connected(encoder)) {
+ drm_info(&dev_priv->drm,
+ "[ENCODER:%d:%s] HPD is down, disabling eDP\n",
+ encoder->base.base.id, encoder->base.name);
+ goto out_vdd_off;
+ }
+
+ /*
+ * Unfortunately even the HPD based detection fails on
+ * eg. Asus B360M-A (CFL+CNP), so as a last resort fall
+ * back to checking for a VGA branch device. Only do this
+ * on known affected platforms to minimize false positives.
+ */
+ if (DISPLAY_VER(dev_priv) == 9 && drm_dp_is_branch(intel_dp->dpcd) &&
+ (intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) ==
+ DP_DWN_STRM_PORT_TYPE_ANALOG) {
+ drm_info(&dev_priv->drm,
+ "[ENCODER:%d:%s] VGA converter detected, disabling eDP\n",
+ encoder->base.base.id, encoder->base.name);
+ goto out_vdd_off;
+ }
}
mutex_lock(&dev_priv->drm.mode_config.mutex);
--
2.41.0
Patch 1 adds the missing lock in memory hotplug operations,
ensuring that the mem_hotplug_lock is held during critical operations
like mhp_init_memmap_on_memory() and mhp_deinit_memmap_on_memory()
Patch 2 deals with error handling in add_memory_resource() and considers
the possibility of altmap support. This ensures proper deallocation of
struct pages, aligning with the allocation strategy.
Patch 3 relocates the vmem_altmap code to sparse-vmemmap.c, enabling the
utilization of vmem_altmap_free() and vmem_altmap_offset() without the
dependency on CONFIG_ZONE_DEVICE.
v2:
* cc: stable(a)vger.kernel.org
* made vmem_altmap_offset()/vmem_altmap_free() inline.
* added Acked-by for patch 1 and patch 2.
v1:
Changes since patch series "implement "memmap on memory" feature on
s390:
Patch 1 (Feedback from David):
* Fixed subject for memory hotplug lock.
* Added locking comments before
memory_block_online()/memory_block_offline().
Patch 2 (Feedback from David):
* Fixed Fixes-by commit.
Patch 3 (lkp report):
* when CONFIG_SPARSEMEM_VMEMMAP is disabled, resolve
undefined reference to `vmem_altmap_offset' error.
* Request for Reviewed-by once again due to the change in patch3.
Thank you
Sumanth Korikkar (3):
mm/memory_hotplug: add missing mem_hotplug_lock
mm/memory_hotplug: fix error handling in add_memory_resource()
mm: use vmem_altmap code without CONFIG_ZONE_DEVICE
drivers/base/memory.c | 18 +++++++++++++++---
include/linux/memremap.h | 12 ------------
include/linux/mm.h | 26 ++++++++++++++++++++++++++
mm/memory_hotplug.c | 15 +++++++--------
mm/memremap.c | 14 +-------------
5 files changed, 49 insertions(+), 36 deletions(-)
--
2.41.0