2013-07-24 06:12:45

by Kuninori Morimoto

[permalink] [raw]
Subject: [PATCH resend] shdma: fixup sh_dmae_get_partial() calculation error

sh_desc->hw.tcr is controlling real data size,
and, register TCR is controlling data transfer count
which was xmit_shifted value of hw.tcr.
Current sh_dmae_get_partial() is calculating in different unit.
This patch fixes it.

Signed-off-by: Kuninori Morimoto <[email protected]>
---
>> Guennadi

Could you please check this patch, and give it your Acked-by ?

drivers/dma/sh/shdma.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
index b70709b..d670b8b 100644
--- a/drivers/dma/sh/shdma.c
+++ b/drivers/dma/sh/shdma.c
@@ -388,8 +388,8 @@ static size_t sh_dmae_get_partial(struct shdma_chan *schan,
shdma_chan);
struct sh_dmae_desc *sh_desc = container_of(sdesc,
struct sh_dmae_desc, shdma_desc);
- return (sh_desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
- sh_chan->xmit_shift;
+ return sh_desc->hw.tcr -
+ (sh_dmae_readl(sh_chan, TCR) << sh_chan->xmit_shift);
}

/* Called from error IRQ or NMI */
--
1.7.9.5


2013-07-24 08:43:56

by Guennadi Liakhovetski

[permalink] [raw]
Subject: Re: [PATCH resend] shdma: fixup sh_dmae_get_partial() calculation error

Hi Morimoto-san

On Tue, 23 Jul 2013, Kuninori Morimoto wrote:

> sh_desc->hw.tcr is controlling real data size,
> and, register TCR is controlling data transfer count
> which was xmit_shifted value of hw.tcr.
> Current sh_dmae_get_partial() is calculating in different unit.
> This patch fixes it.
>
> Signed-off-by: Kuninori Morimoto <[email protected]>

Looks right to me

Acked-by: Guennadi Liakhovetski <[email protected]>

Thanks
Guennadi

> ---
> >> Guennadi
>
> Could you please check this patch, and give it your Acked-by ?
>
> drivers/dma/sh/shdma.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
> index b70709b..d670b8b 100644
> --- a/drivers/dma/sh/shdma.c
> +++ b/drivers/dma/sh/shdma.c
> @@ -388,8 +388,8 @@ static size_t sh_dmae_get_partial(struct shdma_chan *schan,
> shdma_chan);
> struct sh_dmae_desc *sh_desc = container_of(sdesc,
> struct sh_dmae_desc, shdma_desc);
> - return (sh_desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
> - sh_chan->xmit_shift;
> + return sh_desc->hw.tcr -
> + (sh_dmae_readl(sh_chan, TCR) << sh_chan->xmit_shift);
> }
>
> /* Called from error IRQ or NMI */
> --
> 1.7.9.5
>

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

2013-07-26 02:38:33

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH resend] shdma: fixup sh_dmae_get_partial() calculation error

On Wed, Jul 24, 2013 at 10:43:44AM +0200, Guennadi Liakhovetski wrote:
> Hi Morimoto-san
>
> On Tue, 23 Jul 2013, Kuninori Morimoto wrote:
>
> > sh_desc->hw.tcr is controlling real data size,
> > and, register TCR is controlling data transfer count
> > which was xmit_shifted value of hw.tcr.
> > Current sh_dmae_get_partial() is calculating in different unit.
> > This patch fixes it.
> >
> > Signed-off-by: Kuninori Morimoto <[email protected]>
>
> Looks right to me
>
> Acked-by: Guennadi Liakhovetski <[email protected]>

Thanks, I will queue this up for v3.11 in the fixes-for-v3.11 branch.

2013-07-30 08:50:11

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH resend] shdma: fixup sh_dmae_get_partial() calculation error

[ Cc Vinod ]

On Tue, Jul 23, 2013 at 11:12:41PM -0700, Kuninori Morimoto wrote:
> sh_desc->hw.tcr is controlling real data size,
> and, register TCR is controlling data transfer count
> which was xmit_shifted value of hw.tcr.
> Current sh_dmae_get_partial() is calculating in different unit.
> This patch fixes it.
>
> Signed-off-by: Kuninori Morimoto <[email protected]>

Can I confirm that this was a regression introduced by
4f46f8ac80416b0e8fd3aba6a0d842205fb29140
("dmaengine: shdma: restore partial transfer calculation") ?

> ---
> >> Guennadi
>
> Could you please check this patch, and give it your Acked-by ?
>
> drivers/dma/sh/shdma.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
> index b70709b..d670b8b 100644
> --- a/drivers/dma/sh/shdma.c
> +++ b/drivers/dma/sh/shdma.c
> @@ -388,8 +388,8 @@ static size_t sh_dmae_get_partial(struct shdma_chan *schan,
> shdma_chan);
> struct sh_dmae_desc *sh_desc = container_of(sdesc,
> struct sh_dmae_desc, shdma_desc);
> - return (sh_desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
> - sh_chan->xmit_shift;
> + return sh_desc->hw.tcr -
> + (sh_dmae_readl(sh_chan, TCR) << sh_chan->xmit_shift);
> }
>
> /* Called from error IRQ or NMI */
> --
> 1.7.9.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sh" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

2013-07-30 09:22:44

by Guennadi Liakhovetski

[permalink] [raw]
Subject: Re: [PATCH resend] shdma: fixup sh_dmae_get_partial() calculation error

Hi Simon

On Tue, 30 Jul 2013, Simon Horman wrote:

> [ Cc Vinod ]
>
> On Tue, Jul 23, 2013 at 11:12:41PM -0700, Kuninori Morimoto wrote:
> > sh_desc->hw.tcr is controlling real data size,
> > and, register TCR is controlling data transfer count
> > which was xmit_shifted value of hw.tcr.
> > Current sh_dmae_get_partial() is calculating in different unit.
> > This patch fixes it.
> >
> > Signed-off-by: Kuninori Morimoto <[email protected]>
>
> Can I confirm that this was a regression introduced by
> 4f46f8ac80416b0e8fd3aba6a0d842205fb29140
> ("dmaengine: shdma: restore partial transfer calculation") ?

No, don't think so. That patch only restores what was accidentally deleted
from the driver before. So, you cannot say, that before that patch the
calculation was correct. And even the way it restores it was already wrong
before. The error goes back to the original implementation:

commit c014906a870ce70e009def0c9d170ccabeb0be63
Author: Guennadi Liakhovetski <[email protected]>
Date: Thu Feb 18 16:30:02 2010 +0000

dmaengine: shdma: extend .device_terminate_all() to record partial transfer

Thanks
Guennadi

>
> > ---
> > >> Guennadi
> >
> > Could you please check this patch, and give it your Acked-by ?
> >
> > drivers/dma/sh/shdma.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
> > index b70709b..d670b8b 100644
> > --- a/drivers/dma/sh/shdma.c
> > +++ b/drivers/dma/sh/shdma.c
> > @@ -388,8 +388,8 @@ static size_t sh_dmae_get_partial(struct shdma_chan *schan,
> > shdma_chan);
> > struct sh_dmae_desc *sh_desc = container_of(sdesc,
> > struct sh_dmae_desc, shdma_desc);
> > - return (sh_desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
> > - sh_chan->xmit_shift;
> > + return sh_desc->hw.tcr -
> > + (sh_dmae_readl(sh_chan, TCR) << sh_chan->xmit_shift);
> > }
> >
> > /* Called from error IRQ or NMI */
> > --
> > 1.7.9.5
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-sh" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
>

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

2013-07-31 00:52:21

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH resend] shdma: fixup sh_dmae_get_partial() calculation error

On Tue, Jul 30, 2013 at 11:22:31AM +0200, Guennadi Liakhovetski wrote:
> Hi Simon
>
> On Tue, 30 Jul 2013, Simon Horman wrote:
>
> > [ Cc Vinod ]
> >
> > On Tue, Jul 23, 2013 at 11:12:41PM -0700, Kuninori Morimoto wrote:
> > > sh_desc->hw.tcr is controlling real data size,
> > > and, register TCR is controlling data transfer count
> > > which was xmit_shifted value of hw.tcr.
> > > Current sh_dmae_get_partial() is calculating in different unit.
> > > This patch fixes it.
> > >
> > > Signed-off-by: Kuninori Morimoto <[email protected]>
> >
> > Can I confirm that this was a regression introduced by
> > 4f46f8ac80416b0e8fd3aba6a0d842205fb29140
> > ("dmaengine: shdma: restore partial transfer calculation") ?
>
> No, don't think so. That patch only restores what was accidentally deleted
> from the driver before. So, you cannot say, that before that patch the
> calculation was correct. And even the way it restores it was already wrong
> before. The error goes back to the original implementation:
>
> commit c014906a870ce70e009def0c9d170ccabeb0be63
> Author: Guennadi Liakhovetski <[email protected]>
> Date: Thu Feb 18 16:30:02 2010 +0000
>
> dmaengine: shdma: extend .device_terminate_all() to record partial transfer

Thanks, I will add the following to the changelog:

This bug has been present since c014906a870ce70e009def0c9d170ccabeb0be63
("dmaengine: shdma: extend .device_terminate_all() to record partial
transfer"), which was added in 2.6.34-rc1.