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Message-ID: <1556271442.2584.29.camel@pengutronix.de>
Date: Fri, 26 Apr 2019 11:37:22 +0200
From: Lucas Stach <l.stach@...gutronix.de>
To: Robin Gong <yibin.gong@....com>,
"robh+dt@...nel.org" <robh+dt@...nel.org>,
"u.kleine-koenig@...gutronix.de" <u.kleine-koenig@...gutronix.de>,
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Cc: "linux-spi@...r.kernel.org" <linux-spi@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
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<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [EXT] Re: [PATCH v2 06/15] spi: imx: fix ERR009165
Am Freitag, den 26.04.2019, 09:22 +0000 schrieb Robin Gong:
> On 2019-04-26 at 11:07 +0200, Lucas Stach wrote:
> >
> > Am Freitag, den 26.04.2019, 08:05 +0000 schrieb Robin Gong:
> > > static void mx51_setup_wml(struct spi_imx_data *spi_imx)
> > > {
> > > + u32 tx_wml = 0;
> > > +
> >
> > With a wml of 0 you might set the maxburst of the TX dma channel to
> > fifosize to minimize the performance impact of this workaround.
> >
> > Regards,
> > Lucas
>
> Unfortunately, this is a MUST part of errata which cause performance
> drop.
I'm not talking about changing the WML, but when the WML must be 0 you
can safely increase the DMA burst size without overflowing the FIFO,
which might recover some of of the performance loss.
Regards,
Lucas
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