coresight: tmc: fix failure to disable/enable ETF after reading

ETF may fail to re-enable after reading, and driver->reading will
not be set to false, this will cause failure to enable/disable to ETF.
This change set driver->reading to false even if re-enabling fail.

Fixes: 669c4614236a ("coresight: tmc: Don't enable TMC when it's not ready.")
Co-developed-by: Yuanfang Zhang <quic_yuanfang@quicinc.com>
Signed-off-by: Yuanfang Zhang <quic_yuanfang@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
[ Added a comment to explain why we ignore the error ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250507063716.1945213-1-quic_jinlmao@quicinc.com

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 7584cc03d8e60b5b58bb9c1735b6a4f6ffe99e00..0f45ab5e5249933ce7059dfee7fe7376ab33ed2d 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -756,7 +756,6 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
        char *buf = NULL;
        enum tmc_mode mode;
        unsigned long flags;
-       int rc = 0;
 
        /* config types are set a boot time and never change */
        if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB &&
@@ -782,11 +781,11 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
                 * can't be NULL.
                 */
                memset(drvdata->buf, 0, drvdata->size);
-               rc = __tmc_etb_enable_hw(drvdata);
-               if (rc) {
-                       raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
-                       return rc;
-               }
+               /*
+                * Ignore failures to enable the TMC to make sure, we don't
+                * leave the TMC in a "reading" state.
+                */
+               __tmc_etb_enable_hw(drvdata);
        } else {
                /*
                 * The ETB/ETF is not tracing and the buffer was just read.