From d6e90df771ba1888a295362f092f87c760d78e54 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 6 Mar 2026 09:24:41 +0200 Subject: i3c: mipi-i3c-hci: Consolidate spinlocks commit fa12bb903bc3ed1826e355d267fe134bde95e23c upstream. The MIPI I3C HCI driver currently uses separate spinlocks for different contexts (PIO vs. DMA rings). This split is unnecessary and complicates upcoming fixes. The driver does not support concurrent PIO and DMA operation, and it only supports a single DMA ring, so a single lock is sufficient for all paths. Introduce a unified spinlock in struct i3c_hci, switch both PIO and DMA code to use it, and remove the per-context locks. No functional change is intended in this patch. Fixes: 9ad9a52cce282 ("i3c/master: introduce the mipi-i3c-hci driver") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260306072451.11131-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/i3c/master/mipi-i3c-hci/hci.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/i3c/master/mipi-i3c-hci/hci.h') diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h index 249ccb13c909..5656d43a1009 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -45,6 +45,7 @@ struct i3c_hci { const struct hci_io_ops *io; void *io_data; const struct hci_cmd_ops *cmd; + spinlock_t lock; atomic_t next_cmd_tid; u32 caps; unsigned int quirks; -- cgit v1.2.3 From 4faa1e9c67a2229f6749190aedaf88ce0391efd2 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 6 Mar 2026 09:24:43 +0200 Subject: 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 Reviewed-by: Frank Li Link: https://patch.msgid.link/20260306072451.11131-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/i3c/master/mipi-i3c-hci/core.c | 1 + drivers/i3c/master/mipi-i3c-hci/dma.c | 2 ++ drivers/i3c/master/mipi-i3c-hci/hci.h | 1 + 3 files changed, 4 insertions(+) (limited to 'drivers/i3c/master/mipi-i3c-hci/hci.h') diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index 3debc5f1327d..c529c527d722 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; -- cgit v1.2.3