amdgpu_dm_hpd_init() may see connectors without a valid dc_link.
The code already checks dc_link for the polling decision, but later
unconditionally dereferences it when setting up HPD interrupts.
Assign dc_link early and skip connectors where it is NULL.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c:940
amdgpu_dm_hpd_init()
error: we previously assumed 'dc_link' could be null (see line 931)
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c
923 /*
924 * Analog connectors may be hot-plugged unlike other
connector
925 * types that don't support HPD. Only poll analog
connectors.
926 */
927 use_polling |=
928 amdgpu_dm_connector->dc_link &&
^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The patch adds
this NULL check but hopefully it can be removed
929
dc_connector_supports_analog(amdgpu_dm_connector->dc_link->link_id.id);
930
931 dc_link = amdgpu_dm_connector->dc_link;
dc_link assigned here.
932
933 /*
934 * Get a base driver irq reference for hpd ints for the
lifetime
935 * of dm. Note that only hpd interrupt types are
registered with
936 * base driver; hpd_rx types aren't. IOW,
amdgpu_irq_get/put on
937 * hpd_rx isn't available. DM currently controls hpd_rx
938 * explicitly with dc_interrupt_set()
939 */
--> 940 if (dc_link->irq_source_hpd != DC_IRQ_SOURCE_INVALID) {
^^^^^^^^^^^^^^^^^^^^^^^ If it's NULL then we are
trouble because we dereference it here.
941 irq_type = dc_link->irq_source_hpd -
DC_IRQ_SOURCE_HPD1;
942 /*
943 * TODO: There's a mismatch between
mode_info.num_hpd
944 * and what bios reports as the # of connectors
with hpd
Fixes: e07945681dfe ("drm/amd/display: Only poll analog connectors")
Cc: Timur Kristóf <[email protected]>
Cc: Harry Wentland <[email protected]>
Cc: Mario Limonciello <[email protected]>
Cc: Alex Hung <[email protected]>
Cc: Aurabindo Pillai <[email protected]>
Cc: ChiaHsuan Chung <[email protected]>
Cc: Roman Li <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
index e7b0928bd3db..5948e2a6219e 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
@@ -919,16 +919,15 @@ void amdgpu_dm_hpd_init(struct amdgpu_device *adev)
continue;
amdgpu_dm_connector = to_amdgpu_dm_connector(connector);
+ dc_link = amdgpu_dm_connector->dc_link;
+ if (!dc_link)
+ continue;
/*
* Analog connectors may be hot-plugged unlike other connector
* types that don't support HPD. Only poll analog connectors.
*/
- use_polling |=
- amdgpu_dm_connector->dc_link &&
-
dc_connector_supports_analog(amdgpu_dm_connector->dc_link->link_id.id);
-
- dc_link = amdgpu_dm_connector->dc_link;
+ use_polling |=
dc_connector_supports_analog(dc_link->link_id.id);
/*
* Get a base driver irq reference for hpd ints for the lifetime
--
2.34.1
