Jon Povey <[email protected]> writes: > Hi Ben, > > I am not on the i2c list but noticed this pull request: > http://www.spinics.net/linux/lists/linux-i2c/msg04022.html > > I think you have the wrong (old) version of this patch in that branch, > http://git.fluff.org/gitweb?p=bjdooks/linux.git;a=commitdiff;h=4bba0fd8d1c6d405df666e2573e1a1f917098be0 > > The correct v4 one from the start of this thread has more lines > of patch and this commit message:
It is also available in my davinci-i2c branch: git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci.git davinci-i2c Thanks Jon for catching this, Kevin >>>>>> 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 <[email protected]> >>>>>> CC: Sudhakar Rajashekhara <[email protected]> >>>>>> CC: Troy Kisky <[email protected]> > > It also has some more acks and a tested, via Kevin: > >> Acked-by: Troy Kisky <[email protected]> >> Tested-by: Sudhakar Rajashekhara <[email protected]> >> Acked-by: Kevin Hilman <[email protected]> > > > -- > Jon Povey > [email protected] > > Racelogic is a limited company registered in England. Registered number > 2743719 . > Registered Office Unit 10, Swan Business Centre, Osier Way, Buckingham, > Bucks, MK18 1TB . > > The information contained in this electronic mail transmission is intended by > Racelogic Ltd for the use of the named individual or entity to which it is > directed and may contain information that is confidential or privileged. If > you have received this electronic mail transmission in error, please delete > it from your system without copying or forwarding it, and notify the sender > of the error by reply email so that the sender's address records can be > corrected. The views expressed by the sender of this communication do not > necessarily represent those of Racelogic Ltd. Please note that Racelogic > reserves the right to monitor e-mail communications passing through its > network -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
