The current implementation uses a fixed timeout via coresight_timeout(), which may be insufficient when multiple sources are enabled or under heavy load, leading to TMC readiness or flush completion timeout.
This patch introduces a configurable timeout mechanism for flush and tmcready.
Signed-off-by: Yuanfang Zhang quic_yuanfang@quicinc.com --- drivers/hwtracing/coresight/coresight-tmc-core.c | 43 ++++++++++++++++++++++-- 1 file changed, 41 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 88afb16bb6bec395ba535155228d176250f38625..286d56ce88fe80fbfa022946dc798f0f4e72f961 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -8,6 +8,7 @@ #include <linux/kernel.h> #include <linux/init.h> #include <linux/types.h> +#include <linux/delay.h> #include <linux/device.h> #include <linux/idr.h> #include <linux/io.h> @@ -35,13 +36,31 @@ DEFINE_CORESIGHT_DEVLIST(etb_devs, "tmc_etb"); DEFINE_CORESIGHT_DEVLIST(etf_devs, "tmc_etf"); DEFINE_CORESIGHT_DEVLIST(etr_devs, "tmc_etr");
+static u32 tmc_timeout; + +static void tmc_extend_timeout(struct csdev_access *csa, u32 offset, int pos, int val) +{ + int i; + + for (i = tmc_timeout; i > 0; i--) { + if (i - 1) + udelay(1); + } +} + +static int tmc_wait_status(struct csdev_access *csa, u32 offset, int pos, int val) +{ + return coresight_timeout_action(csa, offset, pos, val, + tmc_extend_timeout); +} + int tmc_wait_for_tmcready(struct tmc_drvdata *drvdata) { struct coresight_device *csdev = drvdata->csdev; struct csdev_access *csa = &csdev->access;
/* Ensure formatter, unformatter and hardware fifo are empty */ - if (coresight_timeout(csa, TMC_STS, TMC_STS_TMCREADY_BIT, 1)) { + if (tmc_wait_status(csa, TMC_STS, TMC_STS_TMCREADY_BIT, 1)) { dev_err(&csdev->dev, "timeout while waiting for TMC to be Ready\n"); return -EBUSY; @@ -61,7 +80,7 @@ void tmc_flush_and_stop(struct tmc_drvdata *drvdata) ffcr |= BIT(TMC_FFCR_FLUSHMAN_BIT); writel_relaxed(ffcr, drvdata->base + TMC_FFCR); /* Ensure flush completes */ - if (coresight_timeout(csa, TMC_FFCR, TMC_FFCR_FLUSHMAN_BIT, 0)) { + if (tmc_wait_status(csa, TMC_FFCR, TMC_FFCR_FLUSHMAN_BIT, 0)) { dev_err(&csdev->dev, "timeout while waiting for completion of Manual Flush\n"); } @@ -561,11 +580,31 @@ static ssize_t stop_on_flush_store(struct device *dev,
static DEVICE_ATTR_RW(stop_on_flush);
+static ssize_t timeout_cfg_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return scnprintf(buf, PAGE_SIZE, "%d\n", tmc_timeout); +} + +static ssize_t timeout_cfg_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + unsigned long val; + + if (kstrtoul(buf, 0, &val)) + return -EINVAL; + tmc_timeout = val; + + return size; +} +static DEVICE_ATTR_RW(timeout_cfg);
static struct attribute *coresight_tmc_attrs[] = { &dev_attr_trigger_cntr.attr, &dev_attr_buffer_size.attr, &dev_attr_stop_on_flush.attr, + &dev_attr_timeout_cfg.attr, NULL, };
--- base-commit: 408c97c4a5e0b634dcd15bf8b8808b382e888164 change-id: 20250627-flush_timeout-a598b4c0ce7b
Best regards,