Hi Lubomir, On Monday 02 December 2013 09:17 PM, Lubomir Popov wrote: > Hi Nikita, > > On 28/11/13 18:04, Nikita Kiryanov wrote: >> Writing zero into I2Ci.I2C_CNT register causes random I2C failures in OMAP3 >> based devices. This seems to be related to the following advisory which >> apears in multiple erratas for OMAP3 SoCs (OMAP35xx, DM37xx), as well as >> OMAP4430 TRM: >> >> Advisory: >> I2C Module Does Not Allow 0-Byte Data Requests >> Details: >> When configured as the master, the I2C module does not allow 0-byte data >> transfers. Note: Programming I2Ci.I2C_CNT[15:0]: DCOUNT = 0 will cause >> undefined behavior. >> Workaround(s): >> No workaround. Do not use 0-byte data requests. >> >> The writes in question are unnecessary from a functional point of view. >> Most of them are done after I/O has finished, and the only one that preceds >> I/O (in i2c_probe()) is also unnecessary because a stop bit is sent before >> actual data transmission takes place. >> >> Therefore, remove all writes that zero the cnt register. >> >> Cc: Heiko Schocher <h...@denx.de> >> Cc: Thomas Petazzoni <thomas.petazz...@free-electrons.com> >> Cc: Tom Rini <tr...@ti.com> >> Cc: Lubomir Popov <lpo...@mm-sol.com> >> Cc: Enric Balletbo Serra <eballe...@gmail.com> >> Signed-off-by: Nikita Kiryanov <nik...@compulab.co.il> >> --- >> Changes in V2: >> Removed all instances of writew(0, &i2c_base->cnt) instead of just the >> one in i2c_write (following a test of V1 by Thomas Petazzoni). >> >> > Tested-by: Lubomir Popov <lpo...@mm-sol.com> > > In addition to the OMAP5430/32 tests performed last week, tested today > on OMAP4 (4430/60/70) and on AM3359. Thus tests have covered OMAP4/5- > compatible I2C IPs with revnb_lo=[0x000a to 0x000c] (revnb_hi is 0x5040 > for all those IPs). May I know on top of which tree,tag you are trying this patch ? I tried OMAP4 on top of v2014.01-rc1, but I am not able to boot. I applied this patch and still not able to boot. There is a mail thread going on, on this topic. So I just wanted to know that I am not missing very obvious.
Thanks and regards, Lokesh > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot