Subject: Re: [EXT] Re: [PATCH v2 06/15] spi: imx: fix ERR009165

From: Robin Gong <[email-masked]>
Date: Fri, 26 Apr 2019 09:53:16 +0000

On 2019-04-26 at 11:37 +0200, Lucas Stach wrote:
> 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
Good point, will add it in V3, thanks.
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