From: Thierry Reding <thierry.reding@gmail.com>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Tomasz Figa <tomasz.figa@gmail.com>,
Xiubo Li <Li.Xiubo@freescale.com>,
mark.rutland@arm.com, s.hauer@pengutronix.de,
galak@codeaurora.org, swarren@wwwdotorg.org, t.figa@samsung.com,
grant.likely@linaro.org, matt.porter@linaro.org, rob@landley.net,
ian.campbell@citrix.com, pawel.moll@arm.com,
rob.herring@calxeda.com, linux-arm-kernel@lists.infradead.org,
linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org,
devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
Alison Wang <b18965@freescale.com>,
Jingchang Lu <b35083@freescale.com>
Subject: Re: [PATCHv7 1/4] pwm: Add Freescale FTM PWM driver support
Date: Tue, 17 Dec 2013 14:22:48 +0100 [thread overview]
Message-ID: <20131217132247.GB2329@ulmo.nvidia.com> (raw)
In-Reply-To: <20131217130435.GV4360@n2100.arm.linux.org.uk>
[-- Attachment #1: Type: text/plain, Size: 1269 bytes --]
On Tue, Dec 17, 2013 at 01:04:35PM +0000, Russell King - ARM Linux wrote:
> On Tue, Dec 17, 2013 at 01:54:35PM +0100, Tomasz Figa wrote:
> > On Tuesday 17 of December 2013 13:45:06 Thierry Reding wrote:
> > > I fail to see how that would eliminate the problem with the types. That
> > > said I don't actually see sparse complaining about any type mismatches.
> > > That's probably because the various macros implicitly cast to u32.
> >
> > Well, in BE variant you would read the register using __raw_readl() into
> > a __be32 and then get an u32 from be32_to_cpu() and return it. Similarly
> > for writes
>
> __raw_readl() returns a u32, so you'll get a warning trying to assign a
> u32 to a __be32.
If sparse doesn't complain about the original code here, does that mean
we have a bug that should be fixed?
> We do have ioread32() and ioread32be() which do the appropriate conversion,
> as well as the write versions too. They both include the barrier if you're
> overly concerned about that.
A few years ago GregKH commented in response to a patch that ioread*()
weren't supposed to be used for memory-mapped only devices. The original
purpose apparently was to allow drivers to work with both I/O and
memory-mapped devices.
Thierry
[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: thierry.reding@gmail.com (Thierry Reding)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv7 1/4] pwm: Add Freescale FTM PWM driver support
Date: Tue, 17 Dec 2013 14:22:48 +0100 [thread overview]
Message-ID: <20131217132247.GB2329@ulmo.nvidia.com> (raw)
In-Reply-To: <20131217130435.GV4360@n2100.arm.linux.org.uk>
On Tue, Dec 17, 2013 at 01:04:35PM +0000, Russell King - ARM Linux wrote:
> On Tue, Dec 17, 2013 at 01:54:35PM +0100, Tomasz Figa wrote:
> > On Tuesday 17 of December 2013 13:45:06 Thierry Reding wrote:
> > > I fail to see how that would eliminate the problem with the types. That
> > > said I don't actually see sparse complaining about any type mismatches.
> > > That's probably because the various macros implicitly cast to u32.
> >
> > Well, in BE variant you would read the register using __raw_readl() into
> > a __be32 and then get an u32 from be32_to_cpu() and return it. Similarly
> > for writes
>
> __raw_readl() returns a u32, so you'll get a warning trying to assign a
> u32 to a __be32.
If sparse doesn't complain about the original code here, does that mean
we have a bug that should be fixed?
> We do have ioread32() and ioread32be() which do the appropriate conversion,
> as well as the write versions too. They both include the barrier if you're
> overly concerned about that.
A few years ago GregKH commented in response to a patch that ioread*()
weren't supposed to be used for memory-mapped only devices. The original
purpose apparently was to allow drivers to work with both I/O and
memory-mapped devices.
Thierry
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 836 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20131217/f4f9097f/attachment.sig>
next prev parent reply other threads:[~2013-12-17 13:22 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-13 8:57 [PATCHv7 0/4] Add Freescale FTM PWM driver Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-13 8:57 ` Xiubo Li
[not found] ` <1386925027-16288-1-git-send-email-Li.Xiubo-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
2013-12-13 8:57 ` [PATCHv7 1/4] pwm: Add Freescale FTM PWM driver support Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-17 11:10 ` Thierry Reding
2013-12-17 11:10 ` Thierry Reding
2013-12-17 11:51 ` Russell King - ARM Linux
2013-12-17 11:51 ` Russell King - ARM Linux
2013-12-17 12:00 ` Tomasz Figa
2013-12-17 12:00 ` Tomasz Figa
2013-12-17 12:45 ` Thierry Reding
2013-12-17 12:45 ` Thierry Reding
2013-12-17 12:45 ` Thierry Reding
2013-12-17 12:54 ` Tomasz Figa
2013-12-17 12:54 ` Tomasz Figa
2013-12-17 13:04 ` Russell King - ARM Linux
2013-12-17 13:04 ` Russell King - ARM Linux
2013-12-17 13:08 ` Tomasz Figa
2013-12-17 13:08 ` Tomasz Figa
2013-12-17 13:22 ` Thierry Reding [this message]
2013-12-17 13:22 ` Thierry Reding
2013-12-18 9:43 ` Li.Xiubo
2013-12-18 9:43 ` Li.Xiubo
2013-12-18 9:43 ` Li.Xiubo at freescale.com
2013-12-18 6:28 ` Li.Xiubo
2013-12-18 6:28 ` Li.Xiubo
2013-12-18 6:28 ` Li.Xiubo at freescale.com
2013-12-17 12:24 ` Thierry Reding
2013-12-17 12:24 ` Thierry Reding
2013-12-17 12:58 ` Russell King - ARM Linux
2013-12-17 12:58 ` Russell King - ARM Linux
2013-12-17 13:19 ` Thierry Reding
2013-12-17 13:19 ` Thierry Reding
2013-12-18 3:34 ` Li.Xiubo
2013-12-18 3:34 ` Li.Xiubo at freescale.com
2013-12-13 8:57 ` [PATCHv7 2/4] ARM: dts: Add Freescale FTM PWM node for VF610 Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-13 8:57 ` [PATCHv7 3/4] ARM: dts: Enables FTM PWM device for Vybrid VF610 TOWER board Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-13 8:57 ` [PATCHv7 4/4] Documentation: Add device tree bindings for Freescale FTM PWM Xiubo Li
2013-12-13 8:57 ` Xiubo Li
2013-12-13 8:57 ` Xiubo Li
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20131217132247.GB2329@ulmo.nvidia.com \
--to=thierry.reding@gmail.com \
--cc=Li.Xiubo@freescale.com \
--cc=b18965@freescale.com \
--cc=b35083@freescale.com \
--cc=devicetree@vger.kernel.org \
--cc=galak@codeaurora.org \
--cc=grant.likely@linaro.org \
--cc=ian.campbell@citrix.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=mark.rutland@arm.com \
--cc=matt.porter@linaro.org \
--cc=pawel.moll@arm.com \
--cc=rob.herring@calxeda.com \
--cc=rob@landley.net \
--cc=s.hauer@pengutronix.de \
--cc=swarren@wwwdotorg.org \
--cc=t.figa@samsung.com \
--cc=tomasz.figa@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.