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Commit 80013b87 authored by Tao,Zhang's avatar Tao,Zhang
Browse files

coresight-tmc-etr: Fix deadlock issue while switching mode 



In ETR mode switch stress test, there will be a deadlock issue if
fail to enable ETM source. Since switch mode function will hold
mem_lock and call tmc_disable_etr_sink if ETM failed to be enabled.
Meanwhile, tmc_disable_etr_sink also need to hold mem_lock. Release
mem_lock before calling coresight_enable_all_source_link to fix this
deadlock issue.

Change-Id: I0e9040e79e8ef5278f7b279ce2f7265147ef2b74
Signed-off-by: default avatarTao,Zhang <taozha@codeaurora.org>
parent f1a388a8

drivers/hwtracing/coresight/coresight-tmc-etr.c

+4 −2
Original line number Diff line number Diff line
@@ -2102,23 +2102,25 @@ int tmc_etr_switch_mode(struct tmc_drvdata *drvdata, const char *out_mode) 
		return 0;

	}



	mutex_unlock(&drvdata->mem_lock);

	coresight_disable_all_source_link();

	mutex_lock(&drvdata->mem_lock);

	_tmc_disable_etr_sink(drvdata->csdev, true);

	old_mode = drvdata->out_mode;

	drvdata->out_mode = new_mode;

	if (tmc_enable_etr_sink_sysfs(drvdata->csdev)) {

		drvdata->out_mode = old_mode;

		tmc_enable_etr_sink_sysfs(drvdata->csdev);

		mutex_unlock(&drvdata->mem_lock);

		coresight_enable_all_source_link();

		dev_err(&drvdata->csdev->dev,

			"Switch to %s failed. Fall back to %s.\n",

			str_tmc_etr_out_mode[new_mode],

			str_tmc_etr_out_mode[old_mode]);

		mutex_unlock(&drvdata->mem_lock);

		return -EINVAL;

	}

	coresight_enable_all_source_link();

	mutex_unlock(&drvdata->mem_lock);

	coresight_enable_all_source_link();

	return 0;

}