From: Adrian Hunter Date: Fri, 6 Mar 2026 07:24:49 +0000 (+0200) Subject: i3c: mipi-i3c-hci: Fix race in DMA error handling in interrupt context X-Git-Tag: v7.0-rc4~11^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e44d2719225e618dde74c7056f8e6949f884095e;p=thirdparty%2Fkernel%2Flinux.git i3c: mipi-i3c-hci: Fix race in DMA error handling in interrupt context The DMA ring halts whenever a transfer encounters an error. The interrupt handler previously attempted to detect this situation and restart the ring if a transfer completed at the same time. However, this restart logic runs entirely in interrupt context and is inherently racy: it interacts with other paths manipulating the ring state, and fully serializing it within the interrupt handler is not practical. Move this error-recovery logic out of the interrupt handler and into the transfer-processing path (i3c_hci_process_xfer()), where serialization and state management are already controlled. Introduce a new optional I/O-ops callback, handle_error(), invoked when a completed transfer reports an error. For DMA operation, the implementation simply calls the existing dequeue function, which safely aborts and restarts the ring when needed. This removes the fragile ring-restart logic from the interrupt handler and centralizes error handling where proper sequencing can be ensured. Fixes: ccdb2e0e3b00d ("i3c: mipi-i3c-hci: Add Intel specific quirk to ring resuming") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260306072451.11131-13-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni --- diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index 4a80671536f0..b98952d12d7c 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -223,10 +223,21 @@ int i3c_hci_process_xfer(struct i3c_hci *hci, struct hci_xfer *xfer, int n) if (ret) return ret; - if (!wait_for_completion_timeout(done, timeout) && - hci->io->dequeue_xfer(hci, xfer, n)) { - dev_err(&hci->master.dev, "%s: timeout error\n", __func__); - return -ETIMEDOUT; + if (!wait_for_completion_timeout(done, timeout)) { + if (hci->io->dequeue_xfer(hci, xfer, n)) { + dev_err(&hci->master.dev, "%s: timeout error\n", __func__); + return -ETIMEDOUT; + } + return 0; + } + + if (hci->io->handle_error) { + bool error = false; + + for (int i = 0; i < n && !error; i++) + error = RESP_STATUS(xfer[i].response); + if (error) + return hci->io->handle_error(hci, xfer, n); } return 0; diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 41b83f07fdab..e487ef52f6b4 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -609,6 +609,11 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, return did_unqueue; } +static int hci_dma_handle_error(struct i3c_hci *hci, struct hci_xfer *xfer_list, int n) +{ + return hci_dma_dequeue_xfer(hci, xfer_list, n) ? -EIO : 0; +} + static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh) { u32 op1_val, op2_val, resp, *ring_resp; @@ -870,29 +875,8 @@ static bool hci_dma_irq_handler(struct i3c_hci *hci) hci_dma_xfer_done(hci, rh); if (status & INTR_RING_OP) complete(&rh->op_done); - - if (status & INTR_TRANSFER_ABORT) { - u32 ring_status; - - dev_notice_ratelimited(&hci->master.dev, - "Ring %d: Transfer Aborted\n", i); - mipi_i3c_hci_resume(hci); - ring_status = rh_reg_read(RING_STATUS); - if (!(ring_status & RING_STATUS_RUNNING) && - status & INTR_TRANSFER_COMPLETION && - status & INTR_TRANSFER_ERR) { - /* - * Ring stop followed by run is an Intel - * specific required quirk after resuming the - * halted controller. Do it only when the ring - * is not in running state after a transfer - * error. - */ - rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE); - rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | - RING_CTRL_RUN_STOP); - } - } + if (status & INTR_TRANSFER_ABORT) + dev_dbg(&hci->master.dev, "Ring %d: Transfer Aborted\n", i); if (status & INTR_IBI_RING_FULL) dev_err_ratelimited(&hci->master.dev, "Ring %d: IBI Ring Full Condition\n", i); @@ -908,6 +892,7 @@ const struct hci_io_ops mipi_i3c_hci_dma = { .cleanup = hci_dma_cleanup, .queue_xfer = hci_dma_queue_xfer, .dequeue_xfer = hci_dma_dequeue_xfer, + .handle_error = hci_dma_handle_error, .irq_handler = hci_dma_irq_handler, .request_ibi = hci_dma_request_ibi, .free_ibi = hci_dma_free_ibi, diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h index 850016e3d4fe..9ac9d0e342f4 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -123,6 +123,7 @@ struct hci_io_ops { bool (*irq_handler)(struct i3c_hci *hci); int (*queue_xfer)(struct i3c_hci *hci, struct hci_xfer *xfer, int n); bool (*dequeue_xfer)(struct i3c_hci *hci, struct hci_xfer *xfer, int n); + int (*handle_error)(struct i3c_hci *hci, struct hci_xfer *xfer, int n); int (*request_ibi)(struct i3c_hci *hci, struct i3c_dev_desc *dev, const struct i3c_ibi_setup *req); void (*free_ibi)(struct i3c_hci *hci, struct i3c_dev_desc *dev);