Re: linux-next: manual merge of the dmaengine tree with Linus' tree

[Dave Jiang]

On 5/18/2022 4:46 AM, Vinod Koul wrote:
> On 17-05-22, 15:34, Stephen Rothwell wrote:
> > Hi all,
> >
> > Today's linux-next merge of the dmaengine tree got a conflict in:
> >
> >    drivers/dma/idxd/device.c
> >
> > between commit:
> >
> >    1cd8e751d96c ("dmaengine: idxd: skip clearing device context when device is read-only")
> >
> > from Linus' tree and commit:
> >
> >    cf4ac3fef338 ("dmaengine: idxd: fix lockdep warning on device driver removal")
> Thank you Stephen, the merge looks right to me. Dave pls verify and test
> -next
>
> > from the dmaengine tree.
> >
> > I fixed it up (see below) and can carry the fix as necessary. This
> > is now fixed as far as linux-next is concerned, but any non trivial
> > conflicts should be mentioned to your upstream maintainer when your tree
> > is submitted for merging.  You may also want to consider cooperating
> > with the maintainer of the conflicting tree to minimise any particularly
> > complex conflicts.
> >
> > --
> > Cheers,
> > Stephen Rothwell
> >
> > diff --cc drivers/dma/idxd/device.c
> > index f652da6ab47d,1143886f4a80..000000000000
> > --- a/drivers/dma/idxd/device.c
> > +++ b/drivers/dma/idxd/device.c
> > @@@ -699,21 -716,23 +716,26 @@@ static void idxd_device_wqs_clear_state
> >    		struct idxd_wq *wq = idxd->wqs[i];
> >    
> >    		if (wq->state == IDXD_WQ_ENABLED) {
> > + 			mutex_lock(&wq->wq_lock);
> >    			idxd_wq_disable_cleanup(wq);
> >   -			idxd_wq_device_reset_cleanup(wq);
> >    			wq->state = IDXD_WQ_DISABLED;
> > + 			mutex_unlock(&wq->wq_lock);
> >    		}
> >   +		idxd_wq_device_reset_cleanup(wq);


The lock needs to go around both functions, we can move it outside the 
if().

 + 		mutex_lock(&wq->wq_lock);
  		if (wq->state == IDXD_WQ_ENABLED) {
  			idxd_wq_disable_cleanup(wq);
 -			idxd_wq_device_reset_cleanup(wq);
  			wq->state = IDXD_WQ_DISABLED;
  		}
 +		idxd_wq_device_reset_cleanup(wq);
 + 		mutex_unlock(&wq->wq_lock);


> >    	}
> >    }
> >    
> >    void idxd_device_clear_state(struct idxd_device *idxd)
> >    {
> >   +	if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
> >   +		return;
> >   +
> > + 	idxd_device_wqs_clear_state(idxd);
> > + 	spin_lock(&idxd->dev_lock);
> >    	idxd_groups_clear_state(idxd);
> >    	idxd_engines_clear_state(idxd);
> > - 	idxd_device_wqs_clear_state(idxd);
> > + 	idxd->state = IDXD_DEV_DISABLED;
> > + 	spin_unlock(&idxd->dev_lock);
> >    }
> >    
> >    static void idxd_group_config_write(struct idxd_group *group)