From: jacmet@sunsite.dk (Peter Korsgaard)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] at91sam9g45: fix i2c bus speed
Date: Thu, 23 Sep 2010 12:21:14 +0200 [thread overview]
Message-ID: <87fwx0ahgl.fsf@macbook.be.48ers.dk> (raw)
In-Reply-To: <20100923093104.GA22397@n2100.arm.linux.org.uk> (Russell King's message of "Thu, 23 Sep 2010 10:31:04 +0100")
>>>>> "Russell" == Russell King <- ARM Linux <linux@arm.linux.org.uk>> writes:
Hi,
Russell> udelay(5) should always give something approximating a 5us
Russell> delay, as we calibrate this delay loop against the system
Russell> timer. What I could believe is probably going on here is that
Russell> writing to the hardware is adding additional delays - but
Russell> that's nothing to do with the CPU speed itself.
Well, the gpio handling (sw) overhead is to a certain degree related to
the CPU speed.
--
Bye, Peter Korsgaard
next prev parent reply other threads:[~2010-09-23 10:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-22 9:31 [PATCH] at91sam9g45: fix i2c bus speed Peter Korsgaard
2010-09-22 10:48 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-22 11:08 ` Peter Korsgaard
2010-09-22 14:34 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-22 14:54 ` Wolfgang Wegner
2010-09-22 16:09 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-22 15:18 ` Peter Korsgaard
2010-09-22 16:05 ` Nicolas Ferre
2010-09-22 16:10 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-22 16:06 ` Nicolas Ferre
2010-09-23 8:18 ` Nicolas Ferre
2010-09-23 9:22 ` Peter Korsgaard
2010-09-23 9:31 ` Russell King - ARM Linux
2010-09-23 10:09 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-23 10:24 ` Peter Korsgaard
2010-09-23 10:21 ` Peter Korsgaard [this message]
2010-09-23 10:36 ` Russell King - ARM Linux
2010-09-23 10:54 ` Peter Korsgaard
2010-09-23 11:16 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-23 11:32 ` Peter Korsgaard
2010-09-23 12:00 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-23 11:07 ` Jean-Christophe PLAGNIOL-VILLARD
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