> -----Original Message----- > From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] > Sent: Wednesday, October 06, 2010 2:05 AM > To: Nayak, Rajendra > Cc: Paul Walmsley; Cousson, Benoit; Tony Lindgren; linux-omap@xxxxxxxxxxxxxxx; Varadarajan, Charulatha; Raja, > Govindraj > Subject: Re: [GIT PULL] for testing: OMAP hwmod driver conversions: watchdog, UART, i2c > > "Nayak, Rajendra" <rnayak@xxxxxx> writes: > > >> -----Original Message----- > >> From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] > >> Sent: Wednesday, October 06, 2010 1:19 AM > >> To: Nayak, Rajendra > >> Cc: Paul Walmsley; Cousson, Benoit; Tony Lindgren; linux-omap@xxxxxxxxxxxxxxx; Varadarajan, Charulatha; Raja, > >> Govindraj > >> Subject: Re: [GIT PULL] for testing: OMAP hwmod driver conversions: watchdog, UART, i2c > >> > >> "Nayak, Rajendra" <rnayak@xxxxxx> writes: > >> > >> >> -----Original Message----- > >> >> From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] > >> >> Sent: Tuesday, October 05, 2010 10:34 PM > >> >> To: Nayak, Rajendra > >> >> Cc: Paul Walmsley; Cousson, Benoit; Tony Lindgren; linux-omap@xxxxxxxxxxxxxxx; Varadarajan, Charulatha; > Raja, > >> >> Govindraj > >> >> Subject: Re: [GIT PULL] for testing: OMAP hwmod driver conversions: watchdog, UART, i2c > >> >> > >> >> "Nayak, Rajendra" <rnayak@xxxxxx> writes: > >> >> > >> >> > <snip>.. > >> >> > > >> >> >> > > >> >> >> > Below is an untested patch to provide some mechanism to deal with this -- > >> >> >> > I'd appreciate everyone's comments on this, particularly the comments in > >> >> >> > the patch code on how to deal with this problem. > >> >> >> > >> >> >> Hi Paul, > >> >> >> > >> >> >> I'll test this patch to see if it solves the issue seen with i2c on n800. > >> >> > > >> >> > Hi Paul, Benoit, Kevin, > >> >> > > >> >> > So looks like the issue with i2c on n800 isn't really because of additional > >> >> > delay needed after a clock enable, but related to the omap_readl/writel's > >> >> > done on the 16bit i2c registers as I was suspecting earlier. > >> >> > > >> >> > The below patch fixes the n800 issue for me. My mailer might mess up the alignment > >> >> > hence attaching it too. > >> >> > > >> >> > From af9733f2e63a16b446635d52015e05d631f0788f Mon Sep 17 00:00:00 2001 > >> >> > From: Rajendra Nayak <rnayak@xxxxxx> > >> >> > Date: Tue, 5 Oct 2010 16:36:30 +0530 > >> >> > Subject: [PATCH] OMAP: hwmod: Handle modules with 16bit registers > >> >> > > >> >> > Some modules which have 16bit registers can cause imprecise > >> >> > aborts if a __raw_readl/writel is used to read/write 32 bits. > >> >> > > >> >> > Add an additional flag to identify modules which have such > >> >> > hard requirement, and handle it in the hwmod framework. > >> >> > > >> >> > Signed-off-by: Rajendra Nayak <rnayak@xxxxxx> > >> >> > >> >> Can you also send a corresponding patch to the i2c hwmod data. > >> > Hi Kevin, > >> > > >> > Ok, I'll repost the original patch which adds the omap2 hwmod data with > >> > these flags added for omap2420. Does that sound fine? > >> > >> Since I've alrady done some manual merge conflicts here, you can just > >> post an additional patch and I will fold it in. > > > > Ok, so here's the patch > > ------ > > From 06b4bb7a0ce96776d6d9b344b4786b48fceeffe1 Mon Sep 17 00:00:00 2001 > > From: Rajendra Nayak <rnayak@xxxxxx> > > Date: Wed, 6 Oct 2010 01:49:32 +0530 > > Subject: [PATCH] OMAP2: hmwod: Fix impresice aborts seen on n800/n810 > > > > I2C module on OMAP2420 has 16bit registers and causes imprecise > > aborts if 32bits are read/wriitten into. > > Use the HWMOD_16BIT_REG flag to notify the hmwod framework of this > > hard requirement so that __raw_writew/readw is used to read /write > > the mdoule registers. > > > > Signed-off-by: Rajendra Nayak <rnayak@xxxxxx> > > --- > > arch/arm/mach-omap2/omap_hwmod_2420_data.c | 2 ++ > > 1 files changed, 2 insertions(+), 0 deletions(-) > > Thanks. > > Shouldn't we do the same for 2430? I guess the imprecise aborts aren't > happening on 2430, but I think we should still use the 16-bit accesses > there too. > > What do you think? Yeah, actually i2c modules on all OMAPs including OMAP4 have had 16 bit registers. But somehow only 2420 seemed to cause issues. That's why I mentioned modules with 'hard requirement' :-) Maybe I'll post a patch adding this for all i2c's across OMAP's? > > Kevin -- 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
