Re: [PATCH v3 75/77] ncr5380: Enable PDMA for DTC chips

Hannes Reinecke
2015-12-22T08:08:25Z

On 12/22/2015 02:18 AM, Finn Thain wrote:
> From: Ondrej Zary <linux@rainbow-software.org>
>
> Add I/O register mapping for DTC chips and enable PDMA mode.
>
> These chips have 16-bit wide HOST BUFFER register and it must be read
> by 16-bit accesses (we lose data otherwise).
>
> Large PIO transfers crash at least the DTCT-436P chip (all reads result
> in 0xFF) so this patch actually makes it work.
>
> The chip also crashes when we bang on the C400 host status register too
> heavily after PDMA write - a small udelay is needed.
>
> Tested on DTCT-436P and verified that it does not break 53C400A.
>
> Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
> Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
>
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
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