On Tue, Oct 26, 2010 at 11:04 AM, Nishanth Menon nm@ti.com wrote:
Having a loop with a counter is no timing guarentee for timing accuracy or compiler optimizations. For e.g. the same loop counter which runs when the MPU is running at 600MHz will timeout in around half the time when running at 1GHz. or the example where GCC 4.5 compiles with different optimization compared to GCC 4.4. use timer to keep track of time elapse and we use an emperical number - 1sec for a worst case timeout. This should never happen, and is adequate imaginary condition for us to fail with timeout.
Signed-off-by: Nishanth Menon nm@ti.com
V3: changed the delay logic, removed udelays which was introduced in v2 as the intent was purely to have predictable time delays. the timer logic is based on the discussion in ML using get_timer
V2: http://www.mail-archive.com/u-boot@lists.denx.de/msg40972.html additional cleanups + made MAX_RETRY a macro for reuse throughout the file. tested on PandaBoard with 1GHz boot frequency and GCC4.5 on u-boot 2010.09 + mmc patches. Requesting testing on other platforms
V1: http://www.mail-archive.com/u-boot@lists.denx.de/msg40969.html
Tested on Overo, Beagleboard xM, and Panda. No issues found.
Tested-by: Steve Sakoman steve.sakoman@linaro.org
Steve