[-next,v2] dmaengine: mcf-edma: fix x86_64 allmodconfig compilation warning

[-next,v2] dmaengine: mcf-edma: fix x86_64 allmodconfig compilation warning

[Angelo Dureghello]

This patch fixes the compilation warning reported
during x86_64 allmodconfig build.

Reported-By: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Angelo Dureghello <angelo@sysam.it>
---
Changes for v2:
  - added Reported-By
---
 drivers/dma/mcf-edma.c                     | 3 ++-
 include/linux/platform_data/dma-mcf-edma.h | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c
index 4d30d5302649..e08e2409a102 100644
--- a/drivers/dma/mcf-edma.c
+++ b/drivers/dma/mcf-edma.c
@@ -292,8 +292,9 @@ bool mcf_edma_filter_fn(struct dma_chan *chan, void *param)
 {
 	if (chan->device->dev->driver == &mcf_edma_driver.driver) {
 		struct fsl_edma_chan *mcf_chan = to_fsl_edma_chan(chan);
+		unsigned int req = *(unsigned int *)param;
 
-		return (mcf_chan->slave_id == (u32)param);
+		return (mcf_chan->slave_id == req);
 	}
 
 	return false;
diff --git a/include/linux/platform_data/dma-mcf-edma.h b/include/linux/platform_data/dma-mcf-edma.h
index d718ccfa3421..97cb79bda646 100644
--- a/include/linux/platform_data/dma-mcf-edma.h
+++ b/include/linux/platform_data/dma-mcf-edma.h
@@ -21,7 +21,7 @@ struct dma_slave_map;
 
 bool mcf_edma_filter_fn(struct dma_chan *chan, void *param);
 
-#define MCF_EDMA_FILTER_PARAM(ch)	((void *)ch)
+#define MCF_EDMA_FILTER_PARAM(ch)	((int[]) { (ch) })
 
 /**
  * struct mcf_edma_platform_data - platform specific data for eDMA engine

[-next,v2] dmaengine: mcf-edma: fix x86_64 allmodconfig compilation warning

[Angelo Dureghello]

Hi Geert,

On Fri, Sep 14, 2018 at 02:13:50PM +0200, Angelo Dureghello wrote:
> Hi Geert,
> 
> On Fri, Sep 14, 2018 at 01:35:22PM +0200, Geert Uytterhoeven wrote:
> > Hi Angelo,
> > 
> > Thanks for your patch!
> > 
> > On Fri, Sep 14, 2018 at 9:12 AM Angelo Dureghello <angelo@sysam.it> wrote:
> > > This patch fixes the compilation warning reported
> > > during x86_64 allmodconfig build.
> > 
> > Please quote the warning, so people know what it is about:
> > 
> >     drivers/dma/mcf-edma.c: In function 'mcf_edma_filter_fn':
> >     drivers/dma/mcf-edma.c:296:33: warning: cast from pointer to
> > integer of different size [-Wpointer-to-int-cast]
> >        return (mcf_chan->slave_id == (u32)param);
> > 
> 
> Ok done.
> 
> > > Reported-By: Stephen Rothwell <sfr@canb.auug.org.au>
> > > Signed-off-by: Angelo Dureghello <angelo@sysam.it>
> > > ---
> > > Changes for v2:
> > >   - added Reported-By
> > > ---
> > >  drivers/dma/mcf-edma.c                     | 3 ++-
> > >  include/linux/platform_data/dma-mcf-edma.h | 2 +-
> > >  2 files changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c
> > > index 4d30d5302649..e08e2409a102 100644
> > > --- a/drivers/dma/mcf-edma.c
> > > +++ b/drivers/dma/mcf-edma.c
> > > @@ -292,8 +292,9 @@ bool mcf_edma_filter_fn(struct dma_chan *chan, void *param)
> > >  {
> > >         if (chan->device->dev->driver == &mcf_edma_driver.driver) {
> > >                 struct fsl_edma_chan *mcf_chan = to_fsl_edma_chan(chan);
> > > +               unsigned int req = *(unsigned int *)param;
> > 
> > This looks a bit hackish to me.
> > >
> > > -               return (mcf_chan->slave_id == (u32)param);
> > 
> > The recommended way to cast from pointers to integers is to
> > use uintptr_t, which always has the same size as a pointer, i.e.:
> > 
> 
> slave_id is acually an u32. So, if i understsand, when compiled
> on x86_64 using uintptr_t, the cast should trigger the same issue. 
> I preferred, as i.e. ti/omap dma driver is doing, to simply 
> use a pointer to an int (int[]) as passed type in param,
> so i can then indirectly access the integer. I tested
> proper functionality in ColdFire and that there are no warnings
> anymore in both ColdFire and x86_64 allmodconfig so the patch,
> hopefully, should be legal.  
> 
I misunderstood uintptr_t, verified now that it works fine
for this case, reducing the patch to a single line change.
So switching to it. Thanks !

> >         return (mcf_chan->slave_id == (uintptr_t)param);
> > 
> > > +               return (mcf_chan->slave_id == req);
> > >         }
> > >
> > >         return false;
> > > diff --git a/include/linux/platform_data/dma-mcf-edma.h b/include/linux/platform_data/dma-mcf-edma.h
> > > index d718ccfa3421..97cb79bda646 100644
> > > --- a/include/linux/platform_data/dma-mcf-edma.h
> > > +++ b/include/linux/platform_data/dma-mcf-edma.h
> > > @@ -21,7 +21,7 @@ struct dma_slave_map;
> > >
> > >  bool mcf_edma_filter_fn(struct dma_chan *chan, void *param);
> > >
> > > -#define MCF_EDMA_FILTER_PARAM(ch)      ((void *)ch)
> > > +#define MCF_EDMA_FILTER_PARAM(ch)      ((int[]) { (ch) })
> > >
> > >  /**
> > >   * struct mcf_edma_platform_data - platform specific data for eDMA engine
> > 
> > Gr{oetje,eeting}s,
> > 
> >                         Geert
> > 
> Regards,
> Angelo
> 
> > -- 
> > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> > 
> > In personal conversations with technical people, I call myself a hacker. But
> > when I'm talking to journalists I just say "programmer" or something like that.
> >                                 -- Linus Torvalds

Regards,
Angelo

[-next,v2] dmaengine: mcf-edma: fix x86_64 allmodconfig compilation warning

[Angelo Dureghello]

Hi Geert,

On Fri, Sep 14, 2018 at 01:35:22PM +0200, Geert Uytterhoeven wrote:
> Hi Angelo,
> 
> Thanks for your patch!
> 
> On Fri, Sep 14, 2018 at 9:12 AM Angelo Dureghello <angelo@sysam.it> wrote:
> > This patch fixes the compilation warning reported
> > during x86_64 allmodconfig build.
> 
> Please quote the warning, so people know what it is about:
> 
>     drivers/dma/mcf-edma.c: In function 'mcf_edma_filter_fn':
>     drivers/dma/mcf-edma.c:296:33: warning: cast from pointer to
> integer of different size [-Wpointer-to-int-cast]
>        return (mcf_chan->slave_id == (u32)param);
> 

Ok done.

> > Reported-By: Stephen Rothwell <sfr@canb.auug.org.au>
> > Signed-off-by: Angelo Dureghello <angelo@sysam.it>
> > ---
> > Changes for v2:
> >   - added Reported-By
> > ---
> >  drivers/dma/mcf-edma.c                     | 3 ++-
> >  include/linux/platform_data/dma-mcf-edma.h | 2 +-
> >  2 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c
> > index 4d30d5302649..e08e2409a102 100644
> > --- a/drivers/dma/mcf-edma.c
> > +++ b/drivers/dma/mcf-edma.c
> > @@ -292,8 +292,9 @@ bool mcf_edma_filter_fn(struct dma_chan *chan, void *param)
> >  {
> >         if (chan->device->dev->driver == &mcf_edma_driver.driver) {
> >                 struct fsl_edma_chan *mcf_chan = to_fsl_edma_chan(chan);
> > +               unsigned int req = *(unsigned int *)param;
> 
> This looks a bit hackish to me.
> >
> > -               return (mcf_chan->slave_id == (u32)param);
> 
> The recommended way to cast from pointers to integers is to
> use uintptr_t, which always has the same size as a pointer, i.e.:
> 

slave_id is acually an u32. So, if i understsand, when compiled
on x86_64 using uintptr_t, the cast should trigger the same issue. 
I preferred, as i.e. ti/omap dma driver is doing, to simply 
use a pointer to an int (int[]) as passed type in param,
so i can then indirectly access the integer. I tested
proper functionality in ColdFire and that there are no warnings
anymore in both ColdFire and x86_64 allmodconfig so the patch,
hopefully, should be legal.  

>         return (mcf_chan->slave_id == (uintptr_t)param);
> 
> > +               return (mcf_chan->slave_id == req);
> >         }
> >
> >         return false;
> > diff --git a/include/linux/platform_data/dma-mcf-edma.h b/include/linux/platform_data/dma-mcf-edma.h
> > index d718ccfa3421..97cb79bda646 100644
> > --- a/include/linux/platform_data/dma-mcf-edma.h
> > +++ b/include/linux/platform_data/dma-mcf-edma.h
> > @@ -21,7 +21,7 @@ struct dma_slave_map;
> >
> >  bool mcf_edma_filter_fn(struct dma_chan *chan, void *param);
> >
> > -#define MCF_EDMA_FILTER_PARAM(ch)      ((void *)ch)
> > +#define MCF_EDMA_FILTER_PARAM(ch)      ((int[]) { (ch) })
> >
> >  /**
> >   * struct mcf_edma_platform_data - platform specific data for eDMA engine
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
Regards,
Angelo

> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

[-next,v2] dmaengine: mcf-edma: fix x86_64 allmodconfig compilation warning

[Vinod Koul]

On 14-09-18, 09:11, Angelo Dureghello wrote:
> This patch fixes the compilation warning reported
> during x86_64 allmodconfig build.

How does it do so, I have no clue what to expect. Please describe the
change done here in the log...

Patch title also doesn't tell me anything about the fix.

> 
> Reported-By: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Angelo Dureghello <angelo@sysam.it>
> ---
> Changes for v2:
>   - added Reported-By
> ---
>  drivers/dma/mcf-edma.c                     | 3 ++-
>  include/linux/platform_data/dma-mcf-edma.h | 2 +-
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c
> index 4d30d5302649..e08e2409a102 100644
> --- a/drivers/dma/mcf-edma.c
> +++ b/drivers/dma/mcf-edma.c
> @@ -292,8 +292,9 @@ bool mcf_edma_filter_fn(struct dma_chan *chan, void *param)
>  {
>  	if (chan->device->dev->driver == &mcf_edma_driver.driver) {
>  		struct fsl_edma_chan *mcf_chan = to_fsl_edma_chan(chan);
> +		unsigned int req = *(unsigned int *)param;
>  
> -		return (mcf_chan->slave_id == (u32)param);
> +		return (mcf_chan->slave_id == req);
>  	}
>  
>  	return false;
> diff --git a/include/linux/platform_data/dma-mcf-edma.h b/include/linux/platform_data/dma-mcf-edma.h
> index d718ccfa3421..97cb79bda646 100644
> --- a/include/linux/platform_data/dma-mcf-edma.h
> +++ b/include/linux/platform_data/dma-mcf-edma.h
> @@ -21,7 +21,7 @@ struct dma_slave_map;
>  
>  bool mcf_edma_filter_fn(struct dma_chan *chan, void *param);
>  
> -#define MCF_EDMA_FILTER_PARAM(ch)	((void *)ch)
> +#define MCF_EDMA_FILTER_PARAM(ch)	((int[]) { (ch) })

I dont think you answered me about this, why is this change required and
in the context of current patch, what does it fix?

[-next,v2] dmaengine: mcf-edma: fix x86_64 allmodconfig compilation warning

[Geert Uytterhoeven]

Hi Angelo,

Thanks for your patch!

On Fri, Sep 14, 2018 at 9:12 AM Angelo Dureghello <angelo@sysam.it> wrote:
> This patch fixes the compilation warning reported
> during x86_64 allmodconfig build.

Please quote the warning, so people know what it is about:

    drivers/dma/mcf-edma.c: In function 'mcf_edma_filter_fn':
    drivers/dma/mcf-edma.c:296:33: warning: cast from pointer to
integer of different size [-Wpointer-to-int-cast]
       return (mcf_chan->slave_id == (u32)param);

> Reported-By: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Angelo Dureghello <angelo@sysam.it>
> ---
> Changes for v2:
>   - added Reported-By
> ---
>  drivers/dma/mcf-edma.c                     | 3 ++-
>  include/linux/platform_data/dma-mcf-edma.h | 2 +-
>  2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c
> index 4d30d5302649..e08e2409a102 100644
> --- a/drivers/dma/mcf-edma.c
> +++ b/drivers/dma/mcf-edma.c
> @@ -292,8 +292,9 @@ bool mcf_edma_filter_fn(struct dma_chan *chan, void *param)
>  {
>         if (chan->device->dev->driver == &mcf_edma_driver.driver) {
>                 struct fsl_edma_chan *mcf_chan = to_fsl_edma_chan(chan);
> +               unsigned int req = *(unsigned int *)param;

This looks a bit hackish to me.
>
> -               return (mcf_chan->slave_id == (u32)param);

The recommended way to cast from pointers to integers is to
use uintptr_t, which always has the same size as a pointer, i.e.:

        return (mcf_chan->slave_id == (uintptr_t)param);

> +               return (mcf_chan->slave_id == req);
>         }
>
>         return false;
> diff --git a/include/linux/platform_data/dma-mcf-edma.h b/include/linux/platform_data/dma-mcf-edma.h
> index d718ccfa3421..97cb79bda646 100644
> --- a/include/linux/platform_data/dma-mcf-edma.h
> +++ b/include/linux/platform_data/dma-mcf-edma.h
> @@ -21,7 +21,7 @@ struct dma_slave_map;
>
>  bool mcf_edma_filter_fn(struct dma_chan *chan, void *param);
>
> -#define MCF_EDMA_FILTER_PARAM(ch)      ((void *)ch)
> +#define MCF_EDMA_FILTER_PARAM(ch)      ((int[]) { (ch) })
>
>  /**
>   * struct mcf_edma_platform_data - platform specific data for eDMA engine

Gr{oetje,eeting}s,

                        Geert