From: ezequiel.garcia@free-electrons.com (Ezequiel Garcia)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] dma: mv_xor: Use high_base mmio where appropriate
Date: Tue, 29 Oct 2013 05:34:08 -0300 [thread overview]
Message-ID: <20131029083407.GA2416@localhost> (raw)
In-Reply-To: <CAPcyv4iQVoYCXz16T3N4MbdVJV7MoKKeL0wq9t9WF1Kf3gz3Bw@mail.gmail.com>
On Mon, Oct 28, 2013 at 04:47:20PM -0700, Dan Williams wrote:
> [ adding dmaengine ]
>
> On Mon, Oct 28, 2013 at 3:54 PM, Ezequiel Garcia
> <ezequiel.garcia@free-electrons.com> wrote:
> > Despite requesting two memory resources, called 'base' and 'high_base', the
> > driver uses explicitly only the former. The latter is being used implicitly
> > by addressing at offset +0x200, which in practice accesses high_base.
> >
> > Instead of relying in such trick, let's define the registers with the
> > offset from high_base, and use high_base explicitly where appropriate.
> >
> > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> > ---
> > drivers/dma/mv_xor.c | 3 ++-
> > drivers/dma/mv_xor.h | 25 +++++++++++++------------
> > 2 files changed, 15 insertions(+), 13 deletions(-)
>
> Since it's unused I'd prefer a patch that just deletes xor_high_base.
>
It's wrongly *unused*, the mmio high_base is actually being used
implicitly by always addressing at an offset that addresses +200.
Deleting high_base would actually make it worse, for that region
will no longer be ioremaped. Maybe the commit message is not clear
about it?
--
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
WARNING: multiple messages have this Message-ID (diff)
From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: "linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
sachin.kamat@linaro.org, Vinod Koul <vinod.koul@intel.com>,
dmaengine@vger.kernel.org
Subject: Re: [PATCH 2/2] dma: mv_xor: Use high_base mmio where appropriate
Date: Tue, 29 Oct 2013 05:34:08 -0300 [thread overview]
Message-ID: <20131029083407.GA2416@localhost> (raw)
In-Reply-To: <CAPcyv4iQVoYCXz16T3N4MbdVJV7MoKKeL0wq9t9WF1Kf3gz3Bw@mail.gmail.com>
On Mon, Oct 28, 2013 at 04:47:20PM -0700, Dan Williams wrote:
> [ adding dmaengine ]
>
> On Mon, Oct 28, 2013 at 3:54 PM, Ezequiel Garcia
> <ezequiel.garcia@free-electrons.com> wrote:
> > Despite requesting two memory resources, called 'base' and 'high_base', the
> > driver uses explicitly only the former. The latter is being used implicitly
> > by addressing at offset +0x200, which in practice accesses high_base.
> >
> > Instead of relying in such trick, let's define the registers with the
> > offset from high_base, and use high_base explicitly where appropriate.
> >
> > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> > ---
> > drivers/dma/mv_xor.c | 3 ++-
> > drivers/dma/mv_xor.h | 25 +++++++++++++------------
> > 2 files changed, 15 insertions(+), 13 deletions(-)
>
> Since it's unused I'd prefer a patch that just deletes xor_high_base.
>
It's wrongly *unused*, the mmio high_base is actually being used
implicitly by always addressing at an offset that addresses +200.
Deleting high_base would actually make it worse, for that region
will no longer be ioremaped. Maybe the commit message is not clear
about it?
--
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
next prev parent reply other threads:[~2013-10-29 8:34 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-28 22:54 [PATCH 1/2] dma: mv_xor: Remove unneeded NULL address check Ezequiel Garcia
2013-10-28 22:54 ` Ezequiel Garcia
2013-10-28 22:54 ` [PATCH 2/2] dma: mv_xor: Use high_base mmio where appropriate Ezequiel Garcia
2013-10-28 22:54 ` Ezequiel Garcia
2013-10-28 23:47 ` Dan Williams
2013-10-28 23:47 ` Dan Williams
2013-10-29 8:34 ` Ezequiel Garcia [this message]
2013-10-29 8:34 ` Ezequiel Garcia
2013-10-29 9:32 ` Thomas Petazzoni
2013-10-29 9:32 ` Thomas Petazzoni
2013-10-29 19:15 ` Dan Williams
2013-10-29 19:15 ` Dan Williams
2013-10-29 19:24 ` Thomas Petazzoni
2013-10-29 19:24 ` Thomas Petazzoni
2013-10-30 0:33 ` Ezequiel Garcia
2013-10-30 0:33 ` Ezequiel Garcia
2013-10-30 0:40 ` Dan Williams
2013-10-30 0:40 ` Dan Williams
2013-10-29 9:31 ` [PATCH 1/2] dma: mv_xor: Remove unneeded NULL address check Thomas Petazzoni
2013-10-29 9:31 ` Thomas Petazzoni
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