Re: [PATCH v3 72/77] ncr5380: Fix pseudo DMA transfers on 53C400

From: Hannes Reinecke
Date: Tue Dec 22 2015 - 03:06:46 EST


On 12/22/2015 02:18 AM, Finn Thain wrote:
From: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>

Pseudo-DMA (PDMA) has been broken for ages, resulting in hangs on
53C400-based cards.

According to 53C400 datasheet, PDMA transfer length must be a multiple
of 128. Check if that's true and use PIO if it's not.

This makes PDMA work on 53C400 (Canon FG2-5202).

Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>

Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
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