| Message ID | 1455316144-14464-1-git-send-email-robert.jarzmik@free.fr |
|---|---|
| State | Accepted |
| Commit | 9097103f06332d099c5ab06d1e7f22f4bcaca6e2 |
| Headers | show |
On 12 February 2016 at 19:29, Robert Jarzmik <robert.jarzmik@free.fr> wrote: > When the driver is initialized in a pure device-tree platform, the > driver's probe fails allocating the dma channel : > [ 525.624435] pxa3xx-nand 43100000.nand: no resource defined for data DMA > [ 525.632088] pxa3xx-nand 43100000.nand: alloc nand resource failed > > The reason is that the DMA IO resource is not acquired through platform > resources but by OF bindings. > > Fix this by ensuring that DMA IO resources are only queried in the non > device-tree case. > > Fixes: 8f5ba31aa565 ("mtd: nand: pxa3xx-nand: switch to dmaengine") > Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> > --- > drivers/mtd/nand/pxa3xx_nand.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c > index a168cbcc1086..afd487d4b67f 100644 > --- a/drivers/mtd/nand/pxa3xx_nand.c > +++ b/drivers/mtd/nand/pxa3xx_nand.c > @@ -1750,7 +1750,7 @@ static int alloc_nand_resource(struct platform_device *pdev) > if (ret < 0) > return ret; > > - if (use_dma) { > + if (!np && use_dma) { > r = platform_get_resource(pdev, IORESOURCE_DMA, 0); > if (r == NULL) { > dev_err(&pdev->dev, Looking through the kernel tree, this change seems to be correct. However, I'm still wondering how DMA resources are obtained in the device-tree case. Can you explain it to me?
Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes: > On 12 February 2016 at 19:29, Robert Jarzmik <robert.jarzmik@free.fr> wrote: >> When the driver is initialized in a pure device-tree platform, the >> driver's probe fails allocating the dma channel : >> [ 525.624435] pxa3xx-nand 43100000.nand: no resource defined for data DMA >> [ 525.632088] pxa3xx-nand 43100000.nand: alloc nand resource failed >> >> The reason is that the DMA IO resource is not acquired through platform >> resources but by OF bindings. >> >> Fix this by ensuring that DMA IO resources are only queried in the non >> device-tree case. >> >> Fixes: 8f5ba31aa565 ("mtd: nand: pxa3xx-nand: switch to dmaengine") >> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> >> --- >> drivers/mtd/nand/pxa3xx_nand.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c >> index a168cbcc1086..afd487d4b67f 100644 >> --- a/drivers/mtd/nand/pxa3xx_nand.c >> +++ b/drivers/mtd/nand/pxa3xx_nand.c >> @@ -1750,7 +1750,7 @@ static int alloc_nand_resource(struct platform_device *pdev) >> if (ret < 0) >> return ret; >> >> - if (use_dma) { >> + if (!np && use_dma) { >> r = platform_get_resource(pdev, IORESOURCE_DMA, 0); >> if (r == NULL) { >> dev_err(&pdev->dev, > > Looking through the kernel tree, this change seems to be correct. > > However, I'm still wondering how DMA resources are obtained in the > device-tree case. Can you explain it to me? In the pxa case, look at my extract in [1]. The lines to consider are : dmas = <&pdma 97 3>; dma-names = "data"; Now have a look at the function pxad_dma_xlate() in drivers/dma/pxa_dma.c. You'll see that the "97" ends up in the chanel drcmr, and the "3" in the channel's prio, when the chanel is requested in the nand driver by calling dma_request_slave_channel_compat(). In the latter case, pxad_filter_fn() is not used, it's the pxad_dma_xlate() which is used instead. Is this what you were looking for ? Cheers.
On 27 February 2016 at 07:45, Robert Jarzmik <robert.jarzmik@free.fr> wrote: > Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes: > >> On 12 February 2016 at 19:29, Robert Jarzmik <robert.jarzmik@free.fr> wrote: >>> When the driver is initialized in a pure device-tree platform, the >>> driver's probe fails allocating the dma channel : >>> [ 525.624435] pxa3xx-nand 43100000.nand: no resource defined for data DMA >>> [ 525.632088] pxa3xx-nand 43100000.nand: alloc nand resource failed >>> >>> The reason is that the DMA IO resource is not acquired through platform >>> resources but by OF bindings. >>> >>> Fix this by ensuring that DMA IO resources are only queried in the non >>> device-tree case. >>> >>> Fixes: 8f5ba31aa565 ("mtd: nand: pxa3xx-nand: switch to dmaengine") >>> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> >>> --- >>> drivers/mtd/nand/pxa3xx_nand.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c >>> index a168cbcc1086..afd487d4b67f 100644 >>> --- a/drivers/mtd/nand/pxa3xx_nand.c >>> +++ b/drivers/mtd/nand/pxa3xx_nand.c >>> @@ -1750,7 +1750,7 @@ static int alloc_nand_resource(struct platform_device *pdev) >>> if (ret < 0) >>> return ret; >>> >>> - if (use_dma) { >>> + if (!np && use_dma) { >>> r = platform_get_resource(pdev, IORESOURCE_DMA, 0); >>> if (r == NULL) { >>> dev_err(&pdev->dev, >> >> Looking through the kernel tree, this change seems to be correct. >> >> However, I'm still wondering how DMA resources are obtained in the >> device-tree case. Can you explain it to me? > > In the pxa case, look at my extract in [1]. > The lines to consider are : > dmas = <&pdma 97 3>; > dma-names = "data"; > > Now have a look at the function pxad_dma_xlate() in drivers/dma/pxa_dma.c. > You'll see that the "97" ends up in the chanel drcmr, and the "3" in the > channel's prio, when the chanel is requested in the nand driver by calling > dma_request_slave_channel_compat(). In the latter case, pxad_filter_fn() is not > used, it's the pxad_dma_xlate() which is used instead. > > Is this what you were looking for ? > I see. That's exactly what I was missing. Acked-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> Thanks,
On Fri, Feb 12, 2016 at 11:29:04PM +0100, Robert Jarzmik wrote: > When the driver is initialized in a pure device-tree platform, the > driver's probe fails allocating the dma channel : > [ 525.624435] pxa3xx-nand 43100000.nand: no resource defined for data DMA > [ 525.632088] pxa3xx-nand 43100000.nand: alloc nand resource failed > > The reason is that the DMA IO resource is not acquired through platform > resources but by OF bindings. > > Fix this by ensuring that DMA IO resources are only queried in the non > device-tree case. > > Fixes: 8f5ba31aa565 ("mtd: nand: pxa3xx-nand: switch to dmaengine") > Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Applied to l2-mtd.git
diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c index a168cbcc1086..afd487d4b67f 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -1750,7 +1750,7 @@ static int alloc_nand_resource(struct platform_device *pdev) if (ret < 0) return ret; - if (use_dma) { + if (!np && use_dma) { r = platform_get_resource(pdev, IORESOURCE_DMA, 0); if (r == NULL) { dev_err(&pdev->dev,
When the driver is initialized in a pure device-tree platform, the driver's probe fails allocating the dma channel : [ 525.624435] pxa3xx-nand 43100000.nand: no resource defined for data DMA [ 525.632088] pxa3xx-nand 43100000.nand: alloc nand resource failed The reason is that the DMA IO resource is not acquired through platform resources but by OF bindings. Fix this by ensuring that DMA IO resources are only queried in the non device-tree case. Fixes: 8f5ba31aa565 ("mtd: nand: pxa3xx-nand: switch to dmaengine") Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> --- drivers/mtd/nand/pxa3xx_nand.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)