+ /*
+ * 1)Timeout period = (2^(timeout+13)) SD Clock cycles
+ * 2)Timeout period should be minimum 0.250sec as per SD Card spec
+ * So, 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
+ * As 1) >= 2)
+ * => (2^(timeout+13)) >= mmc->tran_speed * 1/4
+ * Taking log2 both the sides
+ * => timeout + 13 >= log2(mmc->tran_speed/4)
+ * Rounding up to next power of 2
+ * => timeout + 13 = log2(mmc->tran_speed/4) + 1
+ * => timeout + 13 = fls(mmc->tran_speed/4)
+ */
+ timeout = fls(mmc->tran_speed/4);