From: Robin Gong <b38343@freescale.com>
To: Alexander Holler <holler@ahsoftware.de>
Cc: <shawn.guo@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>,
<fugang.duan@freescale.com>
Subject: Re: [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl
Date: Wed, 17 Sep 2014 16:51:08 +0800 [thread overview]
Message-ID: <20140917085106.GB6369@Robin-OptiPlex-780> (raw)
In-Reply-To: <541805E3.6080003@ahsoftware.de>
On Tue, Sep 16, 2014 at 11:41:55AM +0200, Alexander Holler wrote:
> Am 16.09.2014 05:52, schrieb Robin Gong:
> >On Mon, Sep 15, 2014 at 01:50:02PM +0200, Alexander Holler wrote:
> >>Am 10.09.2014 07:30, 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.
> >>
> >>Hmm, I experience problems with DMA too but on uart3. I'm using the same
> >>workaround for the uart (I've just commented out the dma entries in the DT).
> >>The problem manifests itself here such, that brcm_patchram_plus
> >>hangs while uploading the firmware to a BCM4330 connected at uart3
> >>(reproducible).
> >>
> >>So maybe there is a bug in the DMA-engine which not only effects
> >>SPI. Or both drivers contain the same error in handling DMA (maybe
> >>through c&p).
> >>But that's just specualtion from me, I haven't looked further into
> >>that problem.
> >>
> >>Regards,
> >>
> >>Alexander Holler
> >Thanks for your information share. But my issue should be caused by hardware,
> >since everything is ok if it runs on other i.mx6 chip. Is your board also based
> >on i.mx6 chip? If yes, hope you can raise your issue in freescale community or
> >contact with Andy whose mail address added in CC list fugang.duan@freescale.cm.
> >We have fix some bugs in UART DMA case.
>
> It's an i.mx6q (Wandboard quad c1) where I have this problem with
> mainline and much older (but heavily patched freescale 3.10.x based)
> kernels. A quick web-search suggests that this problem exists since
> a long time (noticed mainly by people which try to use BT as this
> seems to be the major use case for high speed serial communication).
>
> Regards,
>
> Alexander Holler
Yes, we just have fixed the BT issue over high speed UART last month. Suggest
you trying our patches based on v3.10.
next prev parent reply other threads:[~2014-09-17 8:44 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-10 5:30 Robin Gong
2014-09-11 8:02 ` Shawn Guo
2014-09-15 9:41 ` Lucas Stach
2014-09-16 1:43 ` Shawn Guo
2014-09-16 3:41 ` Robin Gong
2014-09-16 9:50 ` Lucas Stach
2014-09-17 8:41 ` Robin Gong
2014-09-17 8:55 ` Lucas Stach
2014-09-17 9:19 ` Robin Gong
2014-09-17 9:19 ` Lucas Stach
2014-09-17 9:28 ` Robin Gong
2014-09-15 11:50 ` Alexander Holler
2014-09-16 3:52 ` Robin Gong
2014-09-16 9:41 ` Alexander Holler
2014-09-17 8:51 ` Robin Gong [this message]
2014-09-17 10:56 ` Alexander Holler
2014-10-21 1:06 Robin Gong
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