coresight: cti: Increase reference count when enabling cti (f02b089e) · Commits · 戴 / test

CTI device is enabled when associated coresight device is enabled. Increase the module and device reference count for CTI device when it's enabled. This can prevent CTI device be removed or module be unloaded when CTI device is enabled by an active trace session. Signed-off-by:

Mike Leach <mike.leach@linaro.org> Signed-off-by:

Tingwei Zhang <tingwei@codeaurora.org> Signed-off-by:

Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20200928163513.70169-21-mathieu.poirier@linaro.org Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight.c

+14 −3

Original line number	Diff line number	Diff line
		@@ -241,19 +241,30 @@ coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable)
		{
		int ect_ret = 0;
		struct coresight_device *ect_csdev = csdev->ect_dev;
		struct module *mod;

		if (!ect_csdev)
		return 0;
		if ((!ect_ops(ect_csdev)->enable) \|\| (!ect_ops(ect_csdev)->disable))
		return 0;

		mod = ect_csdev->dev.parent->driver->owner;
		if (enable) {
		if (try_module_get(mod)) {
		ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
		if (!ect_ret)
		if (ect_ret) {
		module_put(mod);
		} else {
		get_device(ect_csdev->dev.parent);
		csdev->ect_enabled = true;
		}
		} else
		ect_ret = -ENODEV;
		} else {
		if (csdev->ect_enabled) {
		ect_ret = ect_ops(ect_csdev)->disable(ect_csdev);
		put_device(ect_csdev->dev.parent);
		module_put(mod);
		csdev->ect_enabled = false;
		}
		}

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