Commits
Dong Aisheng committed 6f9939bd4fa
MLK-9501 dts: imx6sx-sdb: optimize usdhc3 pad settings Detailed reproduce steps: 1. boot-up to Linux command prompt . 2. Plug SD3.0 UHS-I SD Card into SD3 Connector (make sure SD Card running at SD3.0 DDR50/1.8V). 2. write data to SD3 using "dd" command (SD3_CLK running at 1.8V/50MHz). 3. capture the SD3_CLK, SD3_DATA, SD3_CMD waveforms during data write using FET probe (>=1GHz) 4. CLK waveforms like triangular wave are observed. HW team found that the pad setting of the SD3_CLK, SD3_DATA, SD3_CMD signal pins are not optimized. In existing BSP, when running at SD3.0/DDR50/1.8V, SPEED/DSE/SRE = 01/011/1 is used. They propose change it to - SD3_CLK: SPEED/DSE/SRE = 01/110/1. SD3_DATA/SD3_CMD: SPEED/DSE/SRE = 01/101/1. SDHC high speed cards also had such issue(refer to MLK-9500). We only changed the default state (<50Mhz) pad setting, for ultra high speed state like 100Mhz and 200Mhz, it does not have such issue since they already set to the maximum Drive Strength value. Signed-off-by: Dong Aisheng <b29396@freescale.com> (cherry picked from commit 69d4195c741050e0bc78d3005f8ff4f51990d1ae) Conflicts: arch/arm/boot/dts/imx6sx-sdb.dts