"Nayak, Rajendra" <rnayak@xxxxxx> writes: >> -----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. OK, then let's keep this as a targetted fix for this merge window, and we can discuss whether this needs to be done for all OMAPs later. I'll use you current patch, Thanks, 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
