From f02b089e7bddd2f66e63f926960a4e384b1f436d Mon Sep 17 00:00:00 2001 From: Tingwei Zhang Date: Mon, 28 Sep 2020 10:35:08 -0600 Subject: coresight: cti: Increase reference count when enabling cti 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 Signed-off-by: Tingwei Zhang Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20200928163513.70169-21-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'drivers/hwtracing') diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 711beb92166a..546c97045afe 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -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) { - ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); - if (!ect_ret) - csdev->ect_enabled = true; + if (try_module_get(mod)) { + ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); + 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; } } -- cgit v1.2.3