| Message ID | 4deb32b0c7838da66608022c584326eb01d0da03.1642232106.git.christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] dmaengine: qcom_hidma: Remove useless DMA-32 fallback configuration | expand |
On 1/15/2022 2:35 AM, Christophe JAILLET wrote: > As stated in [1], dma_set_mask() with a 64-bit mask never fails if > dev->dma_mask is non-NULL. > So, if it fails, the 32 bits case will also fail for the same reason. > > Simplify code and remove some dead code accordingly. > > [1]: https://lore.kernel.org/linux-kernel/YL3vSPK5DXTNvgdx@infradead.org/#t > Can we please document this? Usual practice was to try allocating 64 bit DMA if possible and fallback to 32 bits. > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > --- > v2: have the subject and updated driver match > --- > drivers/dma/qcom/hidma.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c > index 65d054bb11aa..51587cf8196b 100644 > --- a/drivers/dma/qcom/hidma.c > +++ b/drivers/dma/qcom/hidma.c > @@ -838,9 +838,7 @@ static int hidma_probe(struct platform_device *pdev) > rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > if (rc) { > dev_warn(&pdev->dev, "unable to set coherent mask to 64"); > - rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); > - if (rc) > - goto dmafree; > + goto dmafree; > } > > dmadev->lldev = hidma_ll_init(dmadev->ddev.dev,
Le 22/01/2022 à 19:05, Sinan Kaya a écrit : > On 1/15/2022 2:35 AM, Christophe JAILLET wrote: >> As stated in [1], dma_set_mask() with a 64-bit mask never fails if >> dev->dma_mask is non-NULL. >> So, if it fails, the 32 bits case will also fail for the same reason. >> >> Simplify code and remove some dead code accordingly. >> >> [1]: >> https://lore.kernel.org/linux-kernel/YL3vSPK5DXTNvgdx@infradead.org/#t >> > > Can we please document this? Hi, the patch has been applied, but [1] is sometimes given as an explanation link. CJ [1]: https://lists.linuxfoundation.org/pipermail/iommu/2019-February/033674.html > > Usual practice was to try allocating 64 bit DMA if possible and fallback > to 32 bits. > >> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> >> --- >> v2: have the subject and updated driver match >> --- >> drivers/dma/qcom/hidma.c | 4 +--- >> 1 file changed, 1 insertion(+), 3 deletions(-) >> >> diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c >> index 65d054bb11aa..51587cf8196b 100644 >> --- a/drivers/dma/qcom/hidma.c >> +++ b/drivers/dma/qcom/hidma.c >> @@ -838,9 +838,7 @@ static int hidma_probe(struct platform_device *pdev) >> rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); >> if (rc) { >> dev_warn(&pdev->dev, "unable to set coherent mask to 64"); >> - rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); >> - if (rc) >> - goto dmafree; >> + goto dmafree; >> } >> dmadev->lldev = hidma_ll_init(dmadev->ddev.dev, > >
On 3/19/2022 2:24 AM, Christophe JAILLET wrote: > Le 22/01/2022 à 19:05, Sinan Kaya a écrit : >> On 1/15/2022 2:35 AM, Christophe JAILLET wrote: >>> As stated in [1], dma_set_mask() with a 64-bit mask never fails if >>> dev->dma_mask is non-NULL. >>> So, if it fails, the 32 bits case will also fail for the same reason. >>> >>> Simplify code and remove some dead code accordingly. >>> >>> [1]: >>> https://lore.kernel.org/linux-kernel/YL3vSPK5DXTNvgdx@infradead.org/#t >>> >> >> Can we please document this? > > Hi, the patch has been applied, but [1] is sometimes given as an > explanation link. > > CJ > > > [1]: > https://lists.linuxfoundation.org/pipermail/iommu/2019-February/033674.html Sounds good, please carry my Acked-By: Sinan Kaya <okaya@kernel.org>
diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c index 65d054bb11aa..51587cf8196b 100644 --- a/drivers/dma/qcom/hidma.c +++ b/drivers/dma/qcom/hidma.c @@ -838,9 +838,7 @@ static int hidma_probe(struct platform_device *pdev) rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); if (rc) { dev_warn(&pdev->dev, "unable to set coherent mask to 64"); - rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); - if (rc) - goto dmafree; + goto dmafree; } dmadev->lldev = hidma_ll_init(dmadev->ddev.dev,
As stated in [1], dma_set_mask() with a 64-bit mask never fails if dev->dma_mask is non-NULL. So, if it fails, the 32 bits case will also fail for the same reason. Simplify code and remove some dead code accordingly. [1]: https://lore.kernel.org/linux-kernel/YL3vSPK5DXTNvgdx@infradead.org/#t Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- v2: have the subject and updated driver match --- drivers/dma/qcom/hidma.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)