TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

driver core: Prevent overriding async driver of a device before it probe

Browse Source 
When there are 2 matched drivers for a device using
async probe mechanism, the dev->p->async_driver might
be overridden by the last attached driver.
So just skip the later one if the previous matched driver
was not handled by async thread yet.

Below is my use case which having this problem.

Make both driver mmcblk and mmc_test allow async probe,
the dev->p->async_driver will be overridden by the later driver
mmc_test and bind to the device then claim it for testing.
When it happen, mmcblk will never do probe again.

Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Link: https://lore.kernel.org/r/20220316074328.1801-1-mark-pk.tsai@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mark-PK Tsai
2022-03-16 15:43:28 +08:00
committed by Greg Kroah-Hartman
parent 4c32174a24
commit 84e7c6786a
1 changed files with 2 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/base/dd.c
+2 -1
View File
@@ -1081,6 +1081,7 @@ static void __driver_attach_async_helper(void *_dev, async_cookie_t cookie)
__device_driver_lock(dev, dev->parent);
drv = dev->p->async_driver;
dev->p->async_driver = NULL;
ret = driver_probe_device(drv, dev);
__device_driver_unlock(dev, dev->parent);
@@ -1127,7 +1128,7 @@ static int __driver_attach(struct device *dev, void *data)
*/
dev_dbg(dev, "probing driver %s asynchronously\n", drv->name);
device_lock(dev);
if (!dev->driver) {
if (!dev->driver && !dev->p->async_driver) {
get_device(dev);
dev->p->async_driver = drv;
async_schedule_dev(__driver_attach_async_helper, dev);