"Sudhakar Rajashekhara" <sudhakar....@ti.com> writes: > On Tue, Sep 21, 2010 at 09:43:28, Jon Povey wrote: >> When setting up to transmit, a race exists between the ISR and >> i2c_davinci_xfer_msg() trying to load the first byte and adjust counters. >> This is mostly visible for transmits > 1 byte long. >> >> The hardware starts sending immediately that MDR.STT is set. IMR trickery >> doesn't work because if we start sending, finish the first byte and an >> XRDY event occurs before we load IMR to unmask it, we never get an >> interrupt, and we timeout. >> >> Sudhakar Rajashekhara explains that at least OMAP-L138 requires MDR mode >> settings before DXR for correct behaviour, so load MDR first with >> STT cleared and later load again with STT set. >> >> Tested on DM355 connected to Techwell TW2836 and Wolfson WM8985 >> >> Signed-off-by: Jon Povey <jon.po...@racelogic.co.uk> >> CC: Sudhakar Rajashekhara <sudhakar....@ti.com> >> CC: Troy Kisky <troy.ki...@boundarydevices.com> >> --- > > Tested-by: Sudhakar Rajashekhara <sudhakar....@ti.com> > > Tested with audio loopback on OMAP-L138, OMAP-L137 and DM365. Also tested with > i2cdetect function which probes all the devices on the i2c bus.
Ben, can you queue this one for 2.6.37 with the addition of: Acked-by: Troy Kisky <troy.ki...@boundarydevices.com> Tested-by: Sudhakar Rajashekhara <sudhakar....@ti.com> Acked-by: Kevin Hilman <khil...@deeprootsystems.com> Thanks, Kevin _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
