diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2026-03-06 09:24:43 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-19 16:08:48 +0100 |
| commit | b684b420a5bb0ea1b0e13abfdb8ce41c5266e62e (patch) | |
| tree | cf168b42dbca9697cad3695ea68ff6b3505f4975 | |
| parent | a21d7633358861ef10ed534b9f0445cc6bb22af7 (diff) | |
i3c: mipi-i3c-hci: Fix race in DMA ring dequeue
commit 1dca8aee80eea76d2aae21265de5dd64f6ba0f09 upstream.
The HCI DMA dequeue path (hci_dma_dequeue_xfer()) may be invoked for
multiple transfers that timeout around the same time. However, the
function is not serialized and can race with itself.
When a timeout occurs, hci_dma_dequeue_xfer() stops the ring, processes
incomplete transfers, and then restarts the ring. If another timeout
triggers a parallel call into the same function, the two instances may
interfere with each other - stopping or restarting the ring at unexpected
times.
Add a mutex so that hci_dma_dequeue_xfer() is serialized with respect to
itself.
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/20260306072451.11131-7-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/i3c/master/mipi-i3c-hci/core.c | 1 | ||||
| -rw-r--r-- | drivers/i3c/master/mipi-i3c-hci/dma.c | 2 | ||||
| -rw-r--r-- | drivers/i3c/master/mipi-i3c-hci/hci.h | 1 |
3 files changed, 4 insertions, 0 deletions
diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index e7b36abf1215..c355f4a2baf5 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -632,6 +632,7 @@ static int i3c_hci_init(struct i3c_hci *hci) return ret; spin_lock_init(&hci->lock); + mutex_init(&hci->control_mutex); /* * Now let's reset the hardware. diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 1ed9d053c62f..032753a2bd68 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -486,6 +486,8 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, unsigned int i; bool did_unqueue = false; + guard(mutex)(&hci->control_mutex); + /* stop the ring */ rh_reg_write(RING_CONTROL, RING_CTRL_ABORT); if (wait_for_completion_timeout(&rh->op_done, HZ) == 0) { diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h index 5656d43a1009..32c8aecde9f7 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -46,6 +46,7 @@ struct i3c_hci { void *io_data; const struct hci_cmd_ops *cmd; spinlock_t lock; + struct mutex control_mutex; atomic_t next_cmd_tid; u32 caps; unsigned int quirks; |