From: shawn.guo@freescale.com (Shawn Guo)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl
Date: Tue, 16 Sep 2014 09:43:06 +0800 [thread overview]
Message-ID: <20140916014304.GA23450@dragon> (raw)
In-Reply-To: <1410774073.3314.1.camel@pengutronix.de>
On Mon, Sep 15, 2014 at 11:41:13AM +0200, Lucas Stach wrote:
> Am Mittwoch, den 10.09.2014, 13:30 +0800 schrieb Robin Gong:
> > There is one weird data in rxfifo after one full rx/tx transfer
> > done sometimes. It looks a design issue and hard to workaround
> > totally, so disable dma functhion here. And will re-enable it
> > once the root cause found.
> >
> Sorry, I'm late to this as Shawn seems to already have picked up this
> patch, but this isn't the right way to fix the problem.
>
> We made it clear at kernel summit last year that we try to not break
> existing DTs as booting a new kernel with an old DT is a valid use case.
> While you don't strictly violate this rule what you do here is only
> fixing systems booting with a new DT while leaving others broken.
>
> If you are working around a hardware problem please disable DMA support
> in the driver. This will also allow you to enable it again, if you find
> another workaround without touching the DT again.
Okay, it's a valid point. Patch dropped.
Shawn
WARNING: multiple messages have this Message-ID (diff)
From: Shawn Guo <shawn.guo-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
To: Lucas Stach <l.stach-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Cc: Robin Gong <b38343-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
pawel.moll-5wv7dgnIgG8@public.gmane.org,
mark.rutland-5wv7dgnIgG8@public.gmane.org,
ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org,
galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org,
linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl
Date: Tue, 16 Sep 2014 09:43:06 +0800 [thread overview]
Message-ID: <20140916014304.GA23450@dragon> (raw)
In-Reply-To: <1410774073.3314.1.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
On Mon, Sep 15, 2014 at 11:41:13AM +0200, Lucas Stach wrote:
> Am Mittwoch, den 10.09.2014, 13:30 +0800 schrieb Robin Gong:
> > There is one weird data in rxfifo after one full rx/tx transfer
> > done sometimes. It looks a design issue and hard to workaround
> > totally, so disable dma functhion here. And will re-enable it
> > once the root cause found.
> >
> Sorry, I'm late to this as Shawn seems to already have picked up this
> patch, but this isn't the right way to fix the problem.
>
> We made it clear at kernel summit last year that we try to not break
> existing DTs as booting a new kernel with an old DT is a valid use case.
> While you don't strictly violate this rule what you do here is only
> fixing systems booting with a new DT while leaving others broken.
>
> If you are working around a hardware problem please disable DMA support
> in the driver. This will also allow you to enable it again, if you find
> another workaround without touching the DT again.
Okay, it's a valid point. Patch dropped.
Shawn
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WARNING: multiple messages have this Message-ID (diff)
From: Shawn Guo <shawn.guo@freescale.com>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: Robin Gong <b38343@freescale.com>, <kernel@pengutronix.de>,
<robh+dt@kernel.org>, <pawel.moll@arm.com>,
<mark.rutland@arm.com>, <ijc+devicetree@hellion.org.uk>,
<galak@codeaurora.org>, <linux@arm.linux.org.uk>,
<linux-arm-kernel@lists.infradead.org>,
<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl
Date: Tue, 16 Sep 2014 09:43:06 +0800 [thread overview]
Message-ID: <20140916014304.GA23450@dragon> (raw)
In-Reply-To: <1410774073.3314.1.camel@pengutronix.de>
On Mon, Sep 15, 2014 at 11:41:13AM +0200, Lucas Stach wrote:
> Am Mittwoch, den 10.09.2014, 13:30 +0800 schrieb Robin Gong:
> > There is one weird data in rxfifo after one full rx/tx transfer
> > done sometimes. It looks a design issue and hard to workaround
> > totally, so disable dma functhion here. And will re-enable it
> > once the root cause found.
> >
> Sorry, I'm late to this as Shawn seems to already have picked up this
> patch, but this isn't the right way to fix the problem.
>
> We made it clear at kernel summit last year that we try to not break
> existing DTs as booting a new kernel with an old DT is a valid use case.
> While you don't strictly violate this rule what you do here is only
> fixing systems booting with a new DT while leaving others broken.
>
> If you are working around a hardware problem please disable DMA support
> in the driver. This will also allow you to enable it again, if you find
> another workaround without touching the DT again.
Okay, it's a valid point. Patch dropped.
Shawn
next prev parent reply other threads:[~2014-09-16 1:43 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-10 5:30 [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl Robin Gong
2014-09-10 5:30 ` Robin Gong
2014-09-10 5:30 ` Robin Gong
2014-09-11 8:02 ` Shawn Guo
2014-09-11 8:02 ` Shawn Guo
2014-09-11 8:02 ` Shawn Guo
2014-09-15 9:41 ` Lucas Stach
2014-09-15 9:41 ` Lucas Stach
2014-09-15 9:41 ` Lucas Stach
2014-09-16 1:43 ` Shawn Guo [this message]
2014-09-16 1:43 ` Shawn Guo
2014-09-16 1:43 ` Shawn Guo
2014-09-16 3:41 ` Robin Gong
2014-09-16 3:41 ` Robin Gong
2014-09-16 3:41 ` Robin Gong
2014-09-16 9:50 ` Lucas Stach
2014-09-16 9:50 ` Lucas Stach
2014-09-16 9:50 ` Lucas Stach
2014-09-17 8:41 ` Robin Gong
2014-09-17 8:41 ` Robin Gong
2014-09-17 8:41 ` Robin Gong
2014-09-17 8:55 ` Lucas Stach
2014-09-17 8:55 ` Lucas Stach
2014-09-17 8:55 ` Lucas Stach
2014-09-17 9:19 ` Robin Gong
2014-09-17 9:19 ` Robin Gong
2014-09-17 9:19 ` Robin Gong
2014-09-17 9:19 ` Lucas Stach
2014-09-17 9:19 ` Lucas Stach
2014-09-17 9:19 ` Lucas Stach
2014-09-17 9:28 ` Robin Gong
2014-09-17 9:28 ` Robin Gong
2014-09-17 9:28 ` Robin Gong
2014-09-15 11:50 ` Alexander Holler
2014-09-15 11:50 ` Alexander Holler
2014-09-15 11:50 ` Alexander Holler
2014-09-16 3:52 ` Robin Gong
2014-09-16 3:52 ` Robin Gong
2014-09-16 3:52 ` Robin Gong
2014-09-16 9:41 ` Alexander Holler
2014-09-16 9:41 ` Alexander Holler
2014-09-16 9:41 ` Alexander Holler
2014-09-17 8:51 ` Robin Gong
2014-09-17 8:51 ` Robin Gong
2014-09-17 8:51 ` Robin Gong
2014-09-17 10:56 ` Alexander Holler
2014-09-17 10:56 ` Alexander Holler
2014-09-17 10:56 ` Alexander Holler
-- strict thread matches above, loose matches on Subject: below --
2014-10-21 1:06 Robin Gong
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