On Wed, May 21, 2014 at 10:58:29AM +0200, Maxime Ripard wrote:
> On Wed, May 21, 2014 at 11:01:05AM +0530, Vinod Koul wrote:
> > On Tue, May 13, 2014 at 03:42:58PM +0200, Maxime Ripard wrote:
> > > Hi Vinod,
> > >
> > > On Wed, Apr 30, 2014 at 12:34:08PM +0530, Vinod Koul wrote:
> > > > > +
> > > > > +static int sun6i_dma_terminate_all(struct sun6i_vchan *vchan)
> > > > > +{
> > > > > + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
> > > > > + struct sun6i_pchan *pchan = vchan->phy;
> > > > > + unsigned long flags;
> > > > > + LIST_HEAD(head);
> > > > > +
> > > > > + spin_lock(&sdev->lock);
> > > > > + list_del_init(&vchan->node);
> > > > > + spin_unlock(&sdev->lock);
> > > > > +
> > > > > + spin_lock_irqsave(&vchan->vc.lock, flags);
> > > > > +
> > > > > + vchan_get_all_descriptors(&vchan->vc, &head);
> > > > > +
> > > > > + if (pchan) {
> > > > > + writel(DMA_CHAN_ENABLE_STOP, pchan->base + DMA_CHAN_ENABLE);
> > > > > + writel(DMA_CHAN_PAUSE_RESUME, pchan->base + DMA_CHAN_PAUSE);
> > > > > +
> > > > > + vchan->phy = NULL;
> > > > > + pchan->vchan = NULL;
> > > > > + pchan->desc = NULL;
> > > > > + pchan->done = NULL;
> > > > > + }
> > > > > +
> > > > > + spin_unlock_irqrestore(&vchan->vc.lock, flags);
> > > > > +
> > > > > + vchan_dma_desc_free_list(&vchan->vc, &head);
> > > >
> > > > shouldn't you kill the tasklet as well here?
> > >
> > > Just to be clear, which tasklet? vchan's or the driver's?
> > You need to take care of both. But I suspect if we ensure irq is not triggered
> > and any pending ones are completed you can simply kill both of the tasklets
> > happily. See the fixes merged in dmaengine last cycle (hint: patchlog shows what
> > we need to do)
>
> I still don't get why I should kill the driver tasklet in terminate_all.
>
> The tasklet is common to all the channels, if you kill it, you'll
> prevent it from scheduling while other channels might have had a need
> for it to actually run.
I think I was under the impression that your tasklet is per channel, If that is
not the case it makes no sense then for this case
>
> About the commits themselves, I guess you talk about 9068b032 and
> ccc7aad0. Both these commits only fix the remove path, not the
> terminate_all one, and both these drivers are not doing anything
> related to the tasklet in terminate_all.
Yup as you would have noticed these were not per channel as well
>
> > Btw just noticed, you *should* use dmaengine: as the subsytem name on the patch
> > series...
>
> Ok, I will.
Thanks
--
~Vinod
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