On Fri, Jan 31, 2014 at 01:00:31PM +0100, Geert Uytterhoeven wrote:
One other thing: I haven't tried your patch yet, but I'm afraid the 10 ms may be too small.
E.g. with PIO-based RSPI I don't get more than 2 Mbps, even though spi-max-frequency = <30000000>, due to the PIO and interrupt overhead. Hence a 1 MiB read would take ca. 4s, while your timeout would be 300 ms.
Hrm, I wouldn't have expected something doing PIO in more than one burst to be letting the transfer run in the background. Though I suppose that might make sense in some situations...
I was wondering if that was cutting it a bit fine but more for scheduler reasons, it's what the s3c64xx driver has been using for a while without complaints but may not translate so well with greater exposure.