From 75d42d990335322852ed5f7ce324b701c0949d79 Mon Sep 17 00:00:00 2001 From: Sanman Pradhan Date: Tue, 14 Apr 2026 17:25:12 +0000 Subject: [PATCH] hwtracing: hisi_ptt: Propagate DMA reset timeout in trace_start() hisi_ptt_wait_dma_reset_done() discards the return value of readl_poll_timeout_atomic(). If the DMA engine does not complete its reset within the timeout, hisi_ptt_trace_start() proceeds to start tracing regardless. Return a bool from hisi_ptt_wait_dma_reset_done(), consistent with the other wait helpers in this driver. On timeout, log an error, de-assert the reset bit, and return -ETIMEDOUT. Move ctrl->started to the successful path so a failed start does not leave the trace marked as active. Fixes: ff0de066b463 ("hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan Reviewed-by: Sizhe Liu Reviewed-by: Yicong Yang Tested-by: Sizhe Liu Signed-off-by: Suzuki K Poulose Link: https://lore.kernel.org/r/20260414172451.14331-2-sanman.pradhan@hpe.com --- drivers/hwtracing/ptt/hisi_ptt.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index 94c371c49135..b5d851281fbf 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -171,13 +171,13 @@ static bool hisi_ptt_wait_trace_hw_idle(struct hisi_ptt *hisi_ptt) HISI_PTT_WAIT_TRACE_TIMEOUT_US); } -static void hisi_ptt_wait_dma_reset_done(struct hisi_ptt *hisi_ptt) +static bool hisi_ptt_wait_dma_reset_done(struct hisi_ptt *hisi_ptt) { u32 val; - readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_WR_STS, - val, !val, HISI_PTT_RESET_POLL_INTERVAL_US, - HISI_PTT_RESET_TIMEOUT_US); + return !readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_WR_STS, + val, !val, HISI_PTT_RESET_POLL_INTERVAL_US, + HISI_PTT_RESET_TIMEOUT_US); } static void hisi_ptt_trace_end(struct hisi_ptt *hisi_ptt) @@ -202,14 +202,18 @@ static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt) return -EBUSY; } - ctrl->started = true; - /* Reset the DMA before start tracing */ val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL); val |= HISI_PTT_TRACE_CTRL_RST; writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL); - hisi_ptt_wait_dma_reset_done(hisi_ptt); + if (!hisi_ptt_wait_dma_reset_done(hisi_ptt)) { + pci_err(hisi_ptt->pdev, "timed out waiting for DMA reset\n"); + val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL); + val &= ~HISI_PTT_TRACE_CTRL_RST; + writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL); + return -ETIMEDOUT; + } val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL); val &= ~HISI_PTT_TRACE_CTRL_RST; @@ -234,6 +238,8 @@ static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt) if (!hisi_ptt->trace_ctrl.is_port) val |= HISI_PTT_TRACE_CTRL_FILTER_MODE; + ctrl->started = true; + /* Start the Trace */ val |= HISI_PTT_TRACE_CTRL_EN; writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);