[PATCH 6.6 364/567] i3c: mipi-i3c-hci: Add missing TID field to no-op command descriptor

Greg Kroah-Hartman
2026-03-23T15:10:22Z

6.6-stable review patch. If anyone has any objections, please let me know.

------------------

From: Adrian Hunter <adrian.hunter@intel.com>

commit ec3cfd835f7c4bbd23bc9ad909d2fdc772a578bb upstream.

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@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260306072451.11131-10-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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(-)

--- 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
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -473,7 +473,7 @@ static bool hci_dma_dequeue_xfer(struct
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;