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

From: Lucas Stach
Date: Fri Apr 26 2019 - 05:37:36 EST


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:
> > > Âstatic void mx51_setup_wml(struct spi_imx_data *spi_imx)
> > > Â{
> > > +ÂÂÂÂÂu32 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