Hi Haibo, On 06/10/2015 01:50 AM, Haibo Chen wrote: > i.MX7D support eMMC HS400 mode, this mode can run in 8 bit,200MHZ > DDR mode. So the I/O speed improve a lot compare to SD3.0 > > The default burst length is 8, if we don't change this value, in > HS400 mode, when we do eMMC read operation, we can find that the > clock signal will stop for a period of time. This means the speed > of data moving on AHB bus is slower than I/O speed. So we should > improve the speed of data moving on AHB bus. > > For imx7d usdhc, this patch set the burst length as 16, and set > watermater levle as 64. The test result is the clock signal has > no stop during the eMMC HS400 operation. For other imx usdhc, remain "watermark", not "watermater". > the default value: burst length as 8, watermater level as 16. > Same goes for the subject. Also "levels", not "levles", so: mmc: sdhci-esdhc-imx: config watermark level and burst length -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
