[PATCH V3 09/14] i3c: mipi-i3c-hci: Add missing TID field to no-op command descriptor

Adrian Hunter adrian.hunter at intel.com
Thu Mar 5 23:24:46 PST 2026


The internal control command descriptor used for no-op commands includes a
Transaction ID (TID) field, but the no-op command constructed in
hci_dma_dequeue_xfer() omitted it.  As a result, the hardware receives a
no-op descriptor without the expected TID.

This bug has gone unnoticed because the TID is currently not validated in
the no-op completion path, but the descriptor format requires it to be
present.

Add the missing TID field when generating a no-op descriptor so that its
layout matches the defined command structure.

Fixes: 9ad9a52cce282 ("i3c/master: introduce the mipi-i3c-hci driver")
Cc: stable at vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
Reviewed-by: Frank Li <Frank.Li at nxp.com>
---


Changes in V3:

	None

Changes in V2:

	Add Frank's Rev'd-by


 drivers/i3c/master/mipi-i3c-hci/cmd.h | 1 +
 drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/cmd.h b/drivers/i3c/master/mipi-i3c-hci/cmd.h
index 1d6dd2c5d01a..b1bf87daa651 100644
--- a/drivers/i3c/master/mipi-i3c-hci/cmd.h
+++ b/drivers/i3c/master/mipi-i3c-hci/cmd.h
@@ -17,6 +17,7 @@
 #define CMD_0_TOC			W0_BIT_(31)
 #define CMD_0_ROC			W0_BIT_(30)
 #define CMD_0_ATTR			W0_MASK(2, 0)
+#define CMD_0_TID			W0_MASK(6, 3)
 
 /*
  * Response Descriptor Structure
diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index a3e8e01a35c9..239a195df7c7 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -582,7 +582,7 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci,
 			u32 *ring_data = rh->xfer + rh->xfer_struct_sz * idx;
 
 			/* store no-op cmd descriptor */
-			*ring_data++ = FIELD_PREP(CMD_0_ATTR, 0x7);
+			*ring_data++ = FIELD_PREP(CMD_0_ATTR, 0x7) | FIELD_PREP(CMD_0_TID, xfer->cmd_tid);
 			*ring_data++ = 0;
 			if (hci->cmd == &mipi_i3c_hci_cmd_v2) {
 				*ring_data++ = 0;
-- 
2.51.0




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