Hi Rajendra, On Wed, 11 Apr 2012, Rajendra Nayak wrote: > The changes were done to fix up random L3 interconnect errors that > Anand G was seeing(during i2c reset operation) on some customer platforms. Okay. > I seem to have completely overlooked the I2C_EN programming part done in > omap_i2c_reset() function when I did the patch. No worries. > While the patch did fix the issue for Anand, I guess it > was because of the additional delay post reset, waiting on the > RESETDONE bit and timing out, before accessing the i2c_con register. > So looks like this patch should certainly be reverted but atleast some > platforms/modules (the issue was seen on OMAP4/i2c) will need some > delay between the omap_hwmod_softreset() call and any subsequent module > register accesses. > The patch from Fernando [1] can be quite useful if we can use the > 'srst_udelay' field to populate the appropriate delay needed which can > then be used up in omap_hwmod_softreset() function. > I am out sick today, but I can try some on these lines tomorrow once > I am in office, if the approach seems fine to you. Sorry to hear that - I hope you feel better soon. That approach sounds fine to me, but I don't think Fernando's patch will help with I2C.. Since it uses a custom reset function omap_i2c_reset(), the delay will actually need to go there. Another option though is that it might be possible to generalize the _ocp_softreset() function to handle the I2C/HDQ cases, so they wouldn't need custom reset functions. I'd guess that's probably 3.5 material, though. > Btw, is [1] queued already by you/Benoit to go upstream or are there > issues with it? > > [1] > http://lists.infradead.org/pipermail/linux-arm-kernel/2012-February/086713.html Tony pulled it: http://git.kernel.org/?p=linux/kernel/git/tmlind/linux-omap.git;a=commit;h=b8a633451951d149494076393698880453bf6bfe Not sure when he plans to send it upstream, but I now think it should go up sooner as part of v3.4-rc fixes, to avoid any potential OCP bus errors. - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
