[lkml]   [2006]   [Oct]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 3/3] IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
On Tuesday 03 October 2006 11:03 am, Alan Stern wrote:

> > > Notice another questionable use of hcd->state.
> >
> > Questionable in what way? When that code is called to clean up
> > after driver death, that loop must be ignored ... every pending I/O
> > can safely be scrubbed. That's the main point of that particular
> > HC_IS_RUNNING() test. In other cases, it's essential not to touch
> > DMA queue entries that the host controller is still using.
> Questionable because changes to hcd->state aren't synchronized with the
> driver. In this case it probably doesn't end up making any difference.

The driver changes hcd->state with its spinlock held ... or it did,
last time I audited that code.

> Removing "regs &&" might change other aspects too. For instance, does
> this routine ever get called from a timer routine, where regs would
> normally be NULL? In such situations removing "regs &&" would reverse
> the sense of the test.

As I said in my previous comments: should not be an issue. OHCI doesn't
have timers. That routine is normally called in_irq(), with the other
two call sites being cases where the controller is stopped.

- Dave
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-10-06 05:49    [W:0.055 / U:27.344 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site