[PATCH v2] nvme-apple: Reset q->sq_tail during queue init

[PATCH v2] nvme-apple: Reset q->sq_tail during queue init

[Nick Chan]

Fixes a "duplicate tag error for tag 0" firmware crash during controller
reset while setting up the admin queue on Apple A11 / T8015.

Fixes: 04d8ecf37b5e ("nvme: apple: Add Apple A11 support")
Cc: stable@vger.kernel.org
Suggested-by: Yuriy Havrylyuk <yhavry@gmail.com>
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
---
Changes in v2:
- Cc stable
- Details on how controller reset is fixed
- Link to v1: https://lore.kernel.org/r/20260514-nvme-apple-sq-reset-v1-1-8931e455281e@gmail.com
---
 drivers/nvme/host/apple.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/nvme/host/apple.c b/drivers/nvme/host/apple.c
index 423c9c628e7b..c692fc73babf 100644
--- a/drivers/nvme/host/apple.c
+++ b/drivers/nvme/host/apple.c
@@ -1009,6 +1009,7 @@ static void apple_nvme_init_queue(struct apple_nvme_queue *q)
 	unsigned int depth = apple_nvme_queue_depth(q);
 	struct apple_nvme *anv = queue_to_apple_nvme(q);
 
+	q->sq_tail = 0;
 	q->cq_head = 0;
 	q->cq_phase = 1;
 	if (anv->hw->has_lsq_nvmmu)

---
base-commit: 5d6919055dec134de3c40167a490f33c74c12581
change-id: 20260514-nvme-apple-sq-reset-53e22e88c7b0

Best regards,
-- 
Nick Chan <towinchenmi@gmail.com>

Re: [PATCH v2] nvme-apple: Reset q->sq_tail during queue init

[Sven Peter]

On 14.05.26 15:16, Nick Chan wrote:
> Fixes a "duplicate tag error for tag 0" firmware crash during controller
> reset while setting up the admin queue on Apple A11 / T8015.

... caused by stale entries in the submission queue due to an invalid 
sq_tail offset after reset.

And I guess this also happens on the i/o queue and is fixed by this as 
well, isn't it?


> 
> Fixes: 04d8ecf37b5e ("nvme: apple: Add Apple A11 support")
> Cc: stable@vger.kernel.org
> Suggested-by: Yuriy Havrylyuk <yhavry@gmail.com>
> Signed-off-by: Nick Chan <towinchenmi@gmail.com>
> ---


Reviewed-by: Sven Peter <sven@kernel.org>



Best,


Sven

Re: [PATCH v2] nvme-apple: Reset q->sq_tail during queue init

[Keith Busch]

On Thu, May 14, 2026 at 09:16:01PM +0800, Nick Chan wrote:
> Fixes a "duplicate tag error for tag 0" firmware crash during controller
> reset while setting up the admin queue on Apple A11 / T8015.

Thanks, applied to nvme-7.1.