On Thu, Apr 01, 2010 at 01:15:20AM +0100, Martin Guy wrote: > On 3/25/10, Mika Westerberg <mika.westerb...@iki.fi> wrote: > > > > This patch adds an SPI master driver for the Cirrus EP93xx SPI > > controller found > > > > in EP93xx chips (EP9301, EP9302, EP9307, EP9312 and EP9315). > > > > > > > > Driver currently supports only interrupt driven mode but in future we > > may add > > > > polling mode support as well. > > I've been staring more at this again and it looks (2 clock > strangenesses and extensive control reg setting apart) like good code.
Thanks :) > I have another question: like the Cirrus driver, this takes 100% CPU > doing busy wait for the current transfer to complete. Well it sleeps in ep93xx_spi_process_transfer() while current transfer is complete. It shouldn't busy wait. At least that was not my intention. If you have lot of data to transfer (for example while using mmc_spi), the driver will be very busy. But I can take a look on this and see if there is something wrong. > Given that this driver is interrupt-based, is there any reason why it > can't do something else in the meanwhile? I had an idea that the driver could keep SPI controller interrupts enabled and start next transfer in interrupt handler but I didn't implement that yet, because first I wanted a driver that works. > Not that that's a reason not to include it in 2.6.35 - it works well > and we can think whether to make it more efficient in N+1... Yeah, maybe we can optimize that later. Thank you very much. It is good to hear that someone (else than me) has been using this :) Regards, MW ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
