From a4d362bbed8c86a632b5e22bf64d9c5564e3766e Mon Sep 17 00:00:00 2001 From: Matthew Auld Date: Mon, 10 Jul 2023 10:40:44 +0100 Subject: [PATCH] drm/xe/ct: serialise fast_lock during CT disable MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The fast-path CT could be running as we enter a runtime-suspend or potentially a GT reset, however here we only use the ct->fast_lock and not the full ct->lock. Before disabling the CT, also serialise against the fast_lock to ensure any in-progress work finishes before we start nuking the CT related stuff. Once we disable ct->enabled and drop the lock, any new work should fail gracefully, and anything that was in progress should be finished. Signed-off-by: Matthew Auld Cc: Matthew Brost Cc: José Roberto de Souza Reviewed-by: Matthew Brost Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_guc_ct.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c index ba89db1dcfdb..acf488b00b66 100644 --- a/drivers/gpu/drm/xe/xe_guc_ct.c +++ b/drivers/gpu/drm/xe/xe_guc_ct.c @@ -301,8 +301,10 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct) goto err_out; mutex_lock(&ct->lock); + spin_lock_irq(&ct->fast_lock); ct->g2h_outstanding = 0; ct->enabled = true; + spin_unlock_irq(&ct->fast_lock); mutex_unlock(&ct->lock); smp_mb(); @@ -319,8 +321,10 @@ err_out: void xe_guc_ct_disable(struct xe_guc_ct *ct) { - mutex_lock(&ct->lock); - ct->enabled = false; + mutex_lock(&ct->lock); /* Serialise dequeue_one_g2h() */ + spin_lock_irq(&ct->fast_lock); /* Serialise CT fast-path */ + ct->enabled = false; /* Finally disable CT communication */ + spin_unlock_irq(&ct->fast_lock); mutex_unlock(&ct->lock); xa_destroy(&ct->fence_lookup);