RE: [PATCH -next 7/8] dmaengine: xilinx_dma: Check for both idle and halted state in axidma stop_transfer

[Radhey Shyam Pandey]

> -----Original Message-----
> From: Vinod Koul <vkoul@xxxxxxxxxx>
> Sent: Thursday, September 26, 2019 10:51 PM
> To: Radhey Shyam Pandey <radheys@xxxxxxxxxx>
> Cc: dan.j.williams@xxxxxxxxx; Michal Simek <michals@xxxxxxxxxx>;
> nick.graumann@xxxxxxxxx; andrea.merello@xxxxxxxxx; Appana Durga
> Kedareswara Rao <appanad@xxxxxxxxxx>; mcgrof@xxxxxxxxxx;
> dmaengine@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH -next 7/8] dmaengine: xilinx_dma: Check for both idle
> and halted state in axidma stop_transfer
> 
> On 05-09-19, 22:07, Radhey Shyam Pandey wrote:
> > From: Nicholas Graumann <nick.graumann@xxxxxxxxx>
> >
> > When polling for a stopped transfer in AXI DMA mode, in some cases the
> > status of the channel may indicate IDLE instead of HALTED if the
> > channel was reset due to an error.
> >
> > Signed-off-by: Nicholas Graumann <nick.graumann@xxxxxxxxx>
> > Signed-off-by: Radhey Shyam Pandey
> <radhey.shyam.pandey@xxxxxxxxxx>
> > ---
> >  drivers/dma/xilinx/xilinx_dma.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dma/xilinx/xilinx_dma.c
> b/drivers/dma/xilinx/xilinx_dma.c
> > index b5dd62a..0896e07 100644
> > --- a/drivers/dma/xilinx/xilinx_dma.c
> > +++ b/drivers/dma/xilinx/xilinx_dma.c
> > @@ -1092,8 +1092,9 @@ static int xilinx_dma_stop_transfer(struct
> xilinx_dma_chan *chan)
> >
> >  	/* Wait for the hardware to halt */
> >  	return xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMASR,
> val,
> > -				       val & XILINX_DMA_DMASR_HALTED, 0,
> > -				       XILINX_DMA_LOOP_COUNT);
> > +				       val | (XILINX_DMA_DMASR_IDLE |
> > +					      XILINX_DMA_DMASR_HALTED),
> 
> The condition was bitwise AND and now is OR.. ??

Ah, it should be same as before . Only _IDLE mask should be in OR.

Also on second thought to this patch- we need to describe which error
scenario "in some cases the status of the channel may indicate IDLE
instead of HALTED" as mentioned in commit description.

@Nick: Can you comment?

> 
> > +				       0, XILINX_DMA_LOOP_COUNT);
> >  }
> >
> >  /**
> > --
> > 2.7.4
> 
> --
> ~Vinod