From: Adrian Hunter Date: Fri, 6 Mar 2026 07:24:45 +0000 (+0200) Subject: i3c: mipi-i3c-hci: Correct RING_CTRL_ABORT handling in DMA dequeue X-Git-Tag: v7.0-rc4~11^2~8 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b795e68bf3073d67bebbb5a44d93f49efc5b8cc7;p=thirdparty%2Fkernel%2Fstable.git i3c: mipi-i3c-hci: Correct RING_CTRL_ABORT handling in DMA dequeue The logic used to abort the DMA ring contains several flaws: 1. The driver unconditionally issues a ring abort even when the ring has already stopped. 2. The completion used to wait for abort completion is never re-initialized, resulting in incorrect wait behavior. 3. The abort sequence unintentionally clears RING_CTRL_ENABLE, which resets hardware ring pointers and disrupts the controller state. 4. If the ring is already stopped, the abort operation should be considered successful without attempting further action. Fix the abort handling by checking whether the ring is running before issuing an abort, re-initializing the completion when needed, ensuring that RING_CTRL_ENABLE remains asserted during abort, and treating an already stopped ring as a successful condition. 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/20260306072451.11131-9-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni --- diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index d7840ff69e595..a3e8e01a35c9b 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -546,18 +546,25 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, struct hci_rh_data *rh = &rings->headers[xfer_list[0].ring_number]; unsigned int i; bool did_unqueue = false; + u32 ring_status; 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) { - /* - * We're deep in it if ever this condition is ever met. - * Hardware might still be writing to memory, etc. - */ - dev_crit(&hci->master.dev, "unable to abort the ring\n"); - WARN_ON(1); + ring_status = rh_reg_read(RING_STATUS); + if (ring_status & RING_STATUS_RUNNING) { + /* stop the ring */ + reinit_completion(&rh->op_done); + rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | RING_CTRL_ABORT); + wait_for_completion_timeout(&rh->op_done, HZ); + ring_status = rh_reg_read(RING_STATUS); + if (ring_status & RING_STATUS_RUNNING) { + /* + * We're deep in it if ever this condition is ever met. + * Hardware might still be writing to memory, etc. + */ + dev_crit(&hci->master.dev, "unable to abort the ring\n"); + WARN_ON(1); + } } spin_lock_irq(&hci->lock);