lkml.org 
[lkml]   [2017]   [Oct]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v4 7/8] pwm: Add dummy pwmchip for orphan pwms
On Tue, Oct 17, 2017 at 06:16:23PM +0800, Jeffy Chen wrote:
> When the pwm driver is unbound while the pwm is still requested, the
> pwm core would not actually remove the pwmchip(return -EBUSY instead).
>
> So it would hold some references to the invalid resources(e.g. pwmchip).
>
> And the customer who requested the pwm would have those references too,
> and may crash the kernel when trying to access them later.
>
> Add a dummy pwmchip, and assign orphan pwms to it to avoid that.
>
> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> ---
>
> Changes in v4:
> Fix compile warning.
>
> Changes in v3:
> Assign orphan pwms to dummy pwmchip instead of adding device link in the
> customer driver.

What happened to this? Device links were specifically designed to avoid
situations like these.

A dummy PWM chip doesn't seem like the right solution to this.

Thierry
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2017-10-17 14:41    [W:0.087 / U:4.900 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site