Hi Wolfram, Am Dienstag, den 09.04.2013, 10:32 +0200 schrieb Wolfram Sang: > Hi, > > > A restart transfer is when you just repeat the START condition, without > > putting the device address on the bus again. > > Well, never heard this term before. Where did you get it from? > > > In the MXS driver we put the device address on the bus for every > > transaction we get handed in from the i2c core, so there is never a > > situation where we just repeat the start condition without sending out > > the device address. Before this patch we would not match every > > transaction, but only the last in the list of pending ones, with a STOP > > condition, which is a violation of the spec. > > I still don't get it. You can drop a STOP if you replace it with > a repeated start. In fact, this is crucial in multi-master setups, > otherwise another master could break into your transfer containing > multilple messages. So, if MXS does the right thing on sending START > (doing a correct start sequence), we should not send STOP. If it needs > the STOP to create a correct START, then be it. But then, I'd wonder why > it worked so far... > Ok, I looked this up again and got a nice explanation by Uwe and it seems I based this patch on a wrong interpretation of the spec on my side. I'll resend without this one. Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
