All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mathias Nyman <mathias.nyman@linux.intel.com>
To: uttkarsh.aggarwal@oss.qualcomm.com
Cc: mathias.nyman@linux.intel.com, gregkh@linuxfoundation.org,
	linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
	wesley.cheng@oss.qualcomm.com
Subject: [TESTPATCH] xhci: testpatch add temporary debug to cmd ring handling
Date: Fri,  7 Nov 2025 17:46:03 +0200	[thread overview]
Message-ID: <20251107154604.1301374-1-mathias.nyman@linux.intel.com> (raw)
In-Reply-To: <5e55d9ba-6b4f-4d92-bb47-04b4a68328d2@linux.intel.com>

print messages with CMDDBG prefix if command ring is cleared
with pending commands, or fails to start due to sw state

TESTPATCH

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-ring.c |  5 ++++-
 drivers/usb/host/xhci.c      | 16 ++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index b9e676d37a33..f8029d837428 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -421,8 +421,11 @@ static unsigned int xhci_ring_expansion_needed(struct xhci_hcd *xhci, struct xhc
 /* Ring the host controller doorbell after placing a command on the ring */
 void xhci_ring_cmd_db(struct xhci_hcd *xhci)
 {
-	if (!(xhci->cmd_ring_state & CMD_RING_STATE_RUNNING))
+	if (!(xhci->cmd_ring_state & CMD_RING_STATE_RUNNING)) {
+		xhci_err(xhci, "%pS Failed to start cmd ring, sw cmd_ring_state %d\n",
+			 __builtin_return_address(0), xhci->cmd_ring_state);
 		return;
+	}
 
 	xhci_dbg(xhci, "// Ding dong!\n");
 
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index d3063f796130..fe157813c136 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -504,6 +504,14 @@ static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci)
 	dma_addr_t deq_dma;
 	u64 crcr;
 
+	if (!list_empty(&xhci->cmd_list))
+		xhci_err(xhci, "%pS CMDDBG set cmd ring deq pendig commands\n",
+			 __builtin_return_address(0));
+	if (xhci->cmd_ring->dequeue != xhci->cmd_ring->enqueue)
+		xhci_err(xhci,"%pS CMDDBG set cmd ring deq: %p and enq %p mismatch\n",
+			 __builtin_return_address(0),
+			 xhci->cmd_ring->dequeue, xhci->cmd_ring->enqueue);
+
 	deq_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg, xhci->cmd_ring->dequeue);
 	deq_dma &= CMD_RING_PTR_MASK;
 
@@ -871,6 +879,14 @@ static void xhci_clear_command_ring(struct xhci_hcd *xhci)
 	struct xhci_segment *seg;
 
 	ring = xhci->cmd_ring;
+
+	if (!list_empty(&xhci->cmd_list))
+		xhci_err(xhci, "CMDDBG Clearing command ring with pendig commands\n");
+
+	if (ring->dequeue != ring->enqueue)
+		xhci_err(xhci,"CMDDBG clear cmd ring deq: %p and enq %p mismatch\n",
+			 ring->dequeue, ring->enqueue);
+
 	xhci_for_each_ring_seg(ring->first_seg, seg) {
 		/* erase all TRBs before the link */
 		memset(seg->trbs, 0, sizeof(union xhci_trb) * (TRBS_PER_SEGMENT - 1));
-- 
2.43.0


      parent reply	other threads:[~2025-11-07 15:46 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-22 10:00 [RFC PATCH] usb: host: xhci: Release spinlock before xhci_handshake in command ring abort Uttkarsh Aggarwal
2025-10-22 12:49 ` Mathias Nyman
2025-11-06  9:57   ` Uttkarsh Aggarwal
2025-11-07 13:07     ` Mathias Nyman
2025-11-07 13:11       ` Mathias Nyman
2025-11-07 15:46       ` Mathias Nyman [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20251107154604.1301374-1-mathias.nyman@linux.intel.com \
    --to=mathias.nyman@linux.intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=uttkarsh.aggarwal@oss.qualcomm.com \
    --cc=wesley.cheng@oss.qualcomm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.