* Pais, Allen <allen.pais@xxxxxx> [100201 18:56]: > > ________________________________________ > From: Tony Lindgren [tony@xxxxxxxxxxx] > Sent: Monday, February 01, 2010 7:53 PM > To: Pais, Allen > Cc: linux-omap@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/2] omap: Disable GAIA I2C1/I2C4 internal pull-ups > > Hi, > > * Pais, Allen <allen.pais@xxxxxx> [100121 02:31]: > > From 4044fcc9c517e86fbea9f7d3b15d5cf75a767476 Mon Sep 17 00:00:00 2001 > > From: Allen Pais <allen.pais@xxxxxx> > > Date: Thu, 21 Jan 2010 21:00:04 +0530 > > Subject: [PATCH 1/2] omap: Disable GAIA I2C1/I2C4 internal pull-ups > > > > This patch disables GAIA I2C1 adn I2C4(SR) internal pull-up, to > > use only the external HW resistor >=470 Ohm for the assured > > functionality in HS mode. > > > > While testing the I2C in High Speed mode, it was discovered that > > without a proper pull-up resistor, there is data corruption during > > multi-byte transfer. RTC(time_set) test case was used for testing. > > > > From the analysis done, it was concluded that ideally we need a > > pull-up of 1.6k Ohm(recomended) or atleast 470 Ohm or greater for > > assured performance in HS mode. > > Does this apply to 3630 only, or also 34xx? Is this safe to do > always? > > [Allen] Yes, it does apply to 36xx only. Sounds like then this configuration should be passed from the board-*.c file in platform_data as the external pulls depend on the board. > BTW, once ready it hould be sent to Samuel Ortiz with linux-omap > list Cc'd: > > [Allen] i'll have it sent to Samuel also. Thanks, we can't merge it yet though, see above. Regards, Tony -- 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
