Re: hci_ldsic nested locking problem

From: Felipe Balbi
Date: Thu Mar 20 2014 - 13:37:22 EST


On Thu, Mar 20, 2014 at 01:34:57PM -0400, Peter Hurley wrote:
> [ +cc Huang Shijie ]
>
> On 03/20/2014 01:29 PM, Felipe Balbi wrote:
> >then we need updates to Documentation:
> >
> >Documentation/serial/tty.txt::
> >
> >| Driver Side Interfaces:
> >|
> >| receive_buf() - Hand buffers of bytes from the driver to the ldisc
> >| for processing. Semantics currently rather
> >| mysterious 8(
> >|
> >| write_wakeup() - May be called at any point between open and close.
> >| The TTY_DO_WRITE_WAKEUP flag indicates if a call
> >| is needed but always races versus calls. Thus the
> >| ldisc must be careful about setting order and to
> >| handle unexpected calls. Must not sleep.
> >|
> >| The driver is forbidden from calling this directly
> >| from the ->write call from the ldisc as the ldisc
> >| is permitted to call the driver write method from
> >| this function. In such a situation defer it.
> >
> >documentation says ldisc is allowed to call ->write() from
> >->write_wakeup(). huh ?
>
> Patch submitted but never applied.
>
> http://www.spinics.net/lists/linux-serial/msg11144.html

Thank you. For that patch:

Acked-by: Felipe Balbi <balbi@xxxxxx>

--
balbi

Attachment: signature.asc
Description: Digital signature