From: Shawn Guo <shawnguo@kernel.org>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: kernel@pengutronix.de, Fabio Estevam <festevam@gmail.com>,
NXP Linux Team <linux-imx@nxp.com>,
linux-arm-kernel@lists.infradead.org,
patchwork-lst@pengutronix.de
Subject: Re: [PATCH 0/2] i.MX GPC DMA warning fixes
Date: Sun, 6 Oct 2019 10:06:42 +0800 [thread overview]
Message-ID: <20191006020640.GL7150@dragon> (raw)
In-Reply-To: <20190906103401.22294-1-l.stach@pengutronix.de>
On Fri, Sep 06, 2019 at 12:33:59PM +0200, Lucas Stach wrote:
> Hi all,
>
> those two patches get rid of an annoying boot warning on all i.MX6+
> devices, as the generic OF DMA code tries to forcefully configure the
> DMA capabilities for the virtual GPX power domain devices, which will
> never do any DMA.
>
> This solution isn't the most elegant, as we are making up a 0 DMA mask
> to silence the warning instead of skipping the DMA configuration
> completely. A previous submission of this change for just the GPC v1 [1]
> was shot down for this reason. But then we haven't made any progress in
> fixing this in a better way, as other systems depend on the forceful
> OF DMA configuration to work correctly. So we are stuck between a rock
> and a hard place here.
>
> IMHO we should accept the slight uglyness of this solution in order to
> get rid of the warning now, as it is confusing users into thinking their
> kernel configuration or system setup is faulty, while everything is
> perfectly in order.
>
> Regards,
> Lucas
>
> [1] https://patchwork.kernel.org/patch/10621589/
>
> Lucas Stach (2):
> soc: imx: gpc: set DMA mask for PD platform devices
> soc: imx: gpcv2: set DMA mask for PD platform devices
Please copy Arnd for comments.
Shawn
>
> drivers/soc/imx/gpc.c | 1 +
> drivers/soc/imx/gpcv2.c | 1 +
> 2 files changed, 2 insertions(+)
>
> --
> 2.20.1
>
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prev parent reply other threads:[~2019-10-06 2:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-06 10:33 [PATCH 0/2] i.MX GPC DMA warning fixes Lucas Stach
2019-09-06 10:34 ` [PATCH 1/2] soc: imx: gpc: set DMA mask for PD platform devices Lucas Stach
2019-09-06 10:34 ` [PATCH 2/2] soc: imx: gpcv2: " Lucas Stach
2019-10-06 2:06 ` Shawn Guo [this message]
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