Hello Andy
On 2/12/24 12:53, Andy Shevchenko wrote:
On Mon, Feb 12, 2024 at 1:52 AM George Stark <gnstark@xxxxxxxxxxxxxxxxx> wrote:
I haven't lose hope for the devm_mutex thing and keep pinging those guys
from time to time.
I don't understand. According to v4 thread Christophe proposed on how
the patch should look like. What you need is to incorporate an updated
version into your series. Am I wrong?
We agreed that the effective way of implementing devm_mutex_init() is in
mutex.h using forward declaration of struct device.
The only inconvenient thing is that in the mutex.h mutex_init() declared
after mutex_destroy() so we'll have to use condition #ifdef
CONFIG_DEBUG_MUTEXES twice. Waiman Long proposed great cleanup patch [1]
that eliminates the need of doubling #ifdef. That patch was reviewed a
bit but it's still unapplied (near 2 months). I'm still trying to
contact mutex.h guys but there're no any feedback yet.
[1]
https://lore.kernel.org/lkml/20231216013656.1382213-2-longman@xxxxxxxxxx/T/#m795b230d662c1debb28463ad721ddba5b384340a
Sure I can single out the fix-only patch I'll do it tomorrow.
I believe it can be handled without issuing it separately. `b4` tool
is capable of selective choices. It was rather Q to Lee if he can/want
to apply it right away.
Oh ok, that would be great.
On 2/9/24 20:11, Andy Shevchenko wrote:
On Thu, Dec 21, 2023 at 03:11:11PM +0000, Lee Jones wrote:
On Thu, 14 Dec 2023, George Stark wrote:
This patch series fixes the problem of devm_led_classdev_register misusing.
The basic problem is described in [1]. Shortly when devm_led_classdev_register()
is used then led_classdev_unregister() called after driver's remove() callback.
led_classdev_unregister() calls driver's brightness_set callback and that callback
may use resources which were destroyed already in driver's remove().
After discussion with maintainers [2] [3] we decided:
1) don't touch led subsytem core code and don't remove led_set_brightness() from it
but fix drivers
2) don't use devm_led_classdev_unregister
So the solution is to use devm wrappers for all resources
driver's brightness_set() depends on. And introduce dedicated devm wrapper
for mutex as it's often used resource.
[1] https://lore.kernel.org/lkml/8704539b-ed3b-44e6-aa82-586e2f895e2b@xxxxxxxxxxxxxxxxx/T/
[2] https://lore.kernel.org/lkml/8704539b-ed3b-44e6-aa82-586e2f895e2b@xxxxxxxxxxxxxxxxx/T/#mc132b9b350fa51931b4fcfe14705d9f06e91421f
[3] https://lore.kernel.org/lkml/8704539b-ed3b-44e6-aa82-586e2f895e2b@xxxxxxxxxxxxxxxxx/T/#mdbf572a85c33f869a553caf986b6228bb65c8383
...
FYI: I'll conduct my review once the locking side is settled.
To reduce burden can you apply the first one? It's a fix.
--
Best regards
George
