Messages in this thread | | | Date | Fri, 11 Aug 2023 08:40:16 -0700 | Subject | Re: [PATCH] dmaengine: ioat: fixing the wrong chancnt | From | Dave Jiang <> |
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On 8/11/23 01:16, Yajun Deng wrote: > The chancnt would be updated in __dma_async_device_channel_register(), > but it was assigned in ioat_enumerate_channels(). Therefore chancnt has > the wrong value. > > Clear chancnt before calling dma_async_device_register(). > > Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Thank you for the patch Yajun.
While this may work, it clobbers the chancnt read from the hardware. I think the preferable fix is to move the value read from the hardware in ioat_enumerate_channels() and its current usages to 'struct ioatdma_device' and leave dma->chancnt unchanged in that function so that zeroing it later is not needed.
Also, have you tested this patch or is this just from visual inspection?
And need a fixes tag.
> --- > drivers/dma/ioat/init.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c > index c4602bfc9c74..928fc8a83a36 100644 > --- a/drivers/dma/ioat/init.c > +++ b/drivers/dma/ioat/init.c > @@ -536,8 +536,11 @@ static int ioat_probe(struct ioatdma_device *ioat_dma) > > static int ioat_register(struct ioatdma_device *ioat_dma) > { > - int err = dma_async_device_register(&ioat_dma->dma_dev); > + int err; > + > + ioat_dma->dma_dev.chancnt = 0; > > + err = dma_async_device_register(&ioat_dma->dma_dev); > if (err) { > ioat_disable_interrupts(ioat_dma); > dma_pool_destroy(ioat_dma->completion_pool);
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