From fb472b7a1eb90fc8e4ffc6a30f0e939330fe3fb5 Mon Sep 17 00:00:00 2001
From: Matthew Brost <matthew.brost@intel.com>
Date: Tue, 14 Dec 2021 09:04:59 -0800
Subject: drm/i915/guc: Kick G2H tasklet if no credits
Git-commit: 2aa9f833dd08594584ce2add23a3cd11f0d623bf
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
Let's be paranoid and kick the G2H tasklet, which dequeues messages, if
G2H credits are exhausted.
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211214170500.28569-7-matthew.brost@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
index 741be9abab68..aa6dd6415202 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
@@ -591,12 +591,19 @@ static inline bool h2g_has_room(struct intel_guc_ct *ct, u32 len_dw)
static int has_room_nb(struct intel_guc_ct *ct, u32 h2g_dw, u32 g2h_dw)
{
+ bool h2g = h2g_has_room(ct, h2g_dw);
+ bool g2h = g2h_has_room(ct, g2h_dw);
+
lockdep_assert_held(&ct->ctbs.send.lock);
- if (unlikely(!h2g_has_room(ct, h2g_dw) || !g2h_has_room(ct, g2h_dw))) {
+ if (unlikely(!h2g || !g2h)) {
if (ct->stall_time == KTIME_MAX)
ct->stall_time = ktime_get();
+ /* Be paranoid and kick G2H tasklet to free credits */
+ if (!g2h)
+ tasklet_hi_schedule(&ct->receive_tasklet);
+
if (unlikely(ct_deadlocked(ct)))
return -EPIPE;
else
--
2.38.1