Hi Mark,
On Fri, Jan 31, 2014 at 1:26 PM, Mark Brown broonie@kernel.org wrote:
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...
While I've been thinking about moving more code to the interrupt handler, the current RSPI transfer_one() is indeed still synchronous, so the timeout doesn't apply yet.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds