diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2026-03-06 09:24:43 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-03-11 22:10:01 +0100 |
| commit | 1dca8aee80eea76d2aae21265de5dd64f6ba0f09 (patch) | |
| tree | 9d0c1eb75aee322bf342be8e3b90bbf7bc3f571e | |
| parent | 4decbbc8a8cf0a69ab011d7c2c88ed3cd0a00ddd (diff) | |
i3c: mipi-i3c-hci: Fix race in DMA ring dequeue
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>
| -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 faf5eae2409f..061e84a5c412 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -927,6 +927,7 @@ static int i3c_hci_probe(struct platform_device *pdev) return -ENOMEM; spin_lock_init(&hci->lock); + mutex_init(&hci->control_mutex); /* * Multi-bus instances share the same MMIO address range, but not diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 74b255ad6d0f..f7d411e5e11f 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -547,6 +547,8 @@ 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 f1dd502c071f..9c63d80f7fc4 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -51,6 +51,7 @@ struct i3c_hci { void *io_data; const struct hci_cmd_ops *cmd; spinlock_t lock; + struct mutex control_mutex; atomic_t next_cmd_tid; bool irq_inactive; u32 caps; |