* [PATCH] dw_dmac: apply default dma_mask if needed
@ 2013-01-29 15:06 Andy Shevchenko
2013-01-29 15:23 ` Viresh Kumar
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Andy Shevchenko @ 2013-01-29 15:06 UTC (permalink / raw)
To: Vinod Koul, linux-kernel, spear-devel, Viresh Kumar; +Cc: Andy Shevchenko
In some cases we got the device without dma_mask configured. We have to apply
the default value to avoid crashes during memory mapping.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/dma/dw_dmac.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index e8d0679..a572a1e 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -1673,6 +1673,12 @@ static int dw_probe(struct platform_device *pdev)
if (IS_ERR(regs))
return PTR_ERR(regs);
+ /* Apply default dma_mask if needed */
+ if (!pdev->dev.dma_mask) {
+ pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+ pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+ }
+
dw_params = dma_read_byaddr(regs, DW_PARAMS);
autocfg = dw_params >> DW_PARAMS_EN & 0x1;
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] dw_dmac: apply default dma_mask if needed
2013-01-29 15:06 [PATCH] dw_dmac: apply default dma_mask if needed Andy Shevchenko
@ 2013-01-29 15:23 ` Viresh Kumar
2013-01-29 16:12 ` Arnd Bergmann
2013-01-30 2:06 ` Viresh Kumar
2013-02-12 16:16 ` Vinod Koul
2 siblings, 1 reply; 6+ messages in thread
From: Viresh Kumar @ 2013-01-29 15:23 UTC (permalink / raw)
To: Andy Shevchenko, Arnd Bergmann; +Cc: Vinod Koul, linux-kernel, spear-devel
Adding Arnd in cc.
On 29 January 2013 20:36, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> In some cases we got the device without dma_mask configured. We have to apply
> the default value to avoid crashes during memory mapping.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> drivers/dma/dw_dmac.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> index e8d0679..a572a1e 100644
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -1673,6 +1673,12 @@ static int dw_probe(struct platform_device *pdev)
> if (IS_ERR(regs))
> return PTR_ERR(regs);
>
> + /* Apply default dma_mask if needed */
> + if (!pdev->dev.dma_mask) {
> + pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
> + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> + }
> +
Hmm... Why is it required for a DMA controller? What kind of crash do you
get?
@Arnd: Is this change recommended?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] dw_dmac: apply default dma_mask if needed
2013-01-29 15:23 ` Viresh Kumar
@ 2013-01-29 16:12 ` Arnd Bergmann
0 siblings, 0 replies; 6+ messages in thread
From: Arnd Bergmann @ 2013-01-29 16:12 UTC (permalink / raw)
To: Viresh Kumar
Cc: Andy Shevchenko, Vinod Koul, linux-kernel, spear-devel, Grant Likely
On Tuesday 29 January 2013, Viresh Kumar wrote:
> Adding Arnd in cc.
>
> On 29 January 2013 20:36, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > In some cases we got the device without dma_mask configured. We have to apply
> > the default value to avoid crashes during memory mapping.
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > ---
> > drivers/dma/dw_dmac.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> > index e8d0679..a572a1e 100644
> > --- a/drivers/dma/dw_dmac.c
> > +++ b/drivers/dma/dw_dmac.c
> > @@ -1673,6 +1673,12 @@ static int dw_probe(struct platform_device *pdev)
> > if (IS_ERR(regs))
> > return PTR_ERR(regs);
> >
> > + /* Apply default dma_mask if needed */
> > + if (!pdev->dev.dma_mask) {
> > + pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
> > + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> > + }
> > +
>
> Hmm... Why is it required for a DMA controller? What kind of crash do you
> get?
A valid dma mask is required for any device that is passed into dma_map_*
and other dma-mapping.h interfaces. The question is more about is
responsible for setting up the mask. Traditionally we'd do that from the
platform definition in the place where the platform_device is created,
but this now comes from the device tree, which is a bit inconsistent
with the DMA masks at the moment.
We do set the dev.coherent_dma_mask to DMA_BIT_MASK(32) for all platform
devices instatiated from DT, but I cannot find the code that sets the
dma_mask for a platform_device. For an amba_device, we set both to
the same value. Maybe Grant can remember if the difference here is
intentional, or if the dma_mask is set up elsewhere for a platform_device
coming from DT.
> @Arnd: Is this change recommended?
For all I can tell, it cannot hurt to do it this way.
Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] dw_dmac: apply default dma_mask if needed
2013-01-29 15:06 [PATCH] dw_dmac: apply default dma_mask if needed Andy Shevchenko
2013-01-29 15:23 ` Viresh Kumar
@ 2013-01-30 2:06 ` Viresh Kumar
2013-02-12 16:16 ` Vinod Koul
2 siblings, 0 replies; 6+ messages in thread
From: Viresh Kumar @ 2013-01-30 2:06 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: Vinod Koul, linux-kernel, spear-devel, Arnd Bergmann
On 29 January 2013 20:36, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> In some cases we got the device without dma_mask configured. We have to apply
> the default value to avoid crashes during memory mapping.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> drivers/dma/dw_dmac.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> index e8d0679..a572a1e 100644
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -1673,6 +1673,12 @@ static int dw_probe(struct platform_device *pdev)
> if (IS_ERR(regs))
> return PTR_ERR(regs);
>
> + /* Apply default dma_mask if needed */
> + if (!pdev->dev.dma_mask) {
> + pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
> + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> + }
> +
> dw_params = dma_read_byaddr(regs, DW_PARAMS);
> autocfg = dw_params >> DW_PARAMS_EN & 0x1;
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] dw_dmac: apply default dma_mask if needed
2013-01-29 15:06 [PATCH] dw_dmac: apply default dma_mask if needed Andy Shevchenko
2013-01-29 15:23 ` Viresh Kumar
2013-01-30 2:06 ` Viresh Kumar
@ 2013-02-12 16:16 ` Vinod Koul
2013-02-12 16:53 ` Andy Shevchenko
2 siblings, 1 reply; 6+ messages in thread
From: Vinod Koul @ 2013-02-12 16:16 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: linux-kernel, spear-devel, Viresh Kumar
On Tue, Jan 29, 2013 at 05:06:24PM +0200, Andy Shevchenko wrote:
> In some cases we got the device without dma_mask configured. We have to apply
> the default value to avoid crashes during memory mapping.
>
what was this generated against, it fails to apply for me.
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> drivers/dma/dw_dmac.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> index e8d0679..a572a1e 100644
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -1673,6 +1673,12 @@ static int dw_probe(struct platform_device *pdev)
> if (IS_ERR(regs))
> return PTR_ERR(regs);
>
> + /* Apply default dma_mask if needed */
> + if (!pdev->dev.dma_mask) {
> + pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
> + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> + }
> +
> dw_params = dma_read_byaddr(regs, DW_PARAMS);
> autocfg = dw_params >> DW_PARAMS_EN & 0x1;
>
> --
> 1.7.10.4
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] dw_dmac: apply default dma_mask if needed
2013-02-12 16:16 ` Vinod Koul
@ 2013-02-12 16:53 ` Andy Shevchenko
0 siblings, 0 replies; 6+ messages in thread
From: Andy Shevchenko @ 2013-02-12 16:53 UTC (permalink / raw)
To: Vinod Koul; +Cc: Andy Shevchenko, linux-kernel, spear-devel, Viresh Kumar
On Tue, Feb 12, 2013 at 6:16 PM, Vinod Koul <vinod.koul@intel.com> wrote:
> On Tue, Jan 29, 2013 at 05:06:24PM +0200, Andy Shevchenko wrote:
>> In some cases we got the device without dma_mask configured. We have to apply
>> the default value to avoid crashes during memory mapping.
>>
> what was this generated against, it fails to apply for me.
I've tested this against linux-next. The problem apparently in the
patch which Greg submits earlier:
7331205a "dma: Convert to devm_ioremap_resource()". If you want I
could rebase it against your next branch. I thought you'd seen that
patch already.
>
>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>> ---
>> drivers/dma/dw_dmac.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
>> index e8d0679..a572a1e 100644
>> --- a/drivers/dma/dw_dmac.c
>> +++ b/drivers/dma/dw_dmac.c
>> @@ -1673,6 +1673,12 @@ static int dw_probe(struct platform_device *pdev)
>> if (IS_ERR(regs))
>> return PTR_ERR(regs);
>>
>> + /* Apply default dma_mask if needed */
>> + if (!pdev->dev.dma_mask) {
>> + pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
>> + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
>> + }
>> +
>> dw_params = dma_read_byaddr(regs, DW_PARAMS);
>> autocfg = dw_params >> DW_PARAMS_EN & 0x1;
>>
>> --
>> 1.7.10.4
>>
> --
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--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-02-12 16:53 UTC | newest]
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2013-01-29 15:06 [PATCH] dw_dmac: apply default dma_mask if needed Andy Shevchenko
2013-01-29 15:23 ` Viresh Kumar
2013-01-29 16:12 ` Arnd Bergmann
2013-01-30 2:06 ` Viresh Kumar
2013-02-12 16:16 ` Vinod Koul
2013-02-12 16:53 ` Andy Shevchenko
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