On 03/01/2011 11:12 AM, Priyanka Jain wrote:
Timeout counter value is set as DTOCV bits in SYSCTL register For counter value set as timeout, Timeout period = (2^(timeout + 13)) SD Clock cycles
As per 4.6.2.2 section of SD Card specification v2.00, host should cofigure timeout period value to minimum 0.25 sec.
Number of SD Clock cycles for 0.25sec should be minimum (SD Clock/sec * 0.25 sec) SD Clock cycles = (mmc->tran_speed * 1/4) SD Clock cycles
Calculating timeout based on (2^(timeout + 13)) >= mmc->tran_speed * 1/4 Taking log2 both the sides and rounding up to next power of 2 => timeout + 13 = log2(mmc->tran_speed/4) + 1
Signed-off-by: Priyanka Jain Priyanka.Jain@freescale.com Signed-off-by: Andy Fleming afleming@freescale.com Signed-off-by: Kumar Gala galak@kernel.crashing.org Acked-by: Mingkai Hu Mingkai.Hu@freescale.com
It seems to me that this patch is set on top of V1 of the same patch instead of top of u-boot. Changes are related only to comments and the new formula for timeout is already applied.
Best regards, Stefano Babic