diff options
| author | Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com> | 2018-07-17 16:24:43 +0200 |
|---|---|---|
| committer | Christoph Muellner <christoph.muellner@theobroma-systems.com> | 2019-04-30 20:01:59 +0200 |
| commit | 1c72e34163c78cb07ca2dbfc7766f576c9c52fa8 (patch) | |
| tree | 130f95e3b7889506cf802f2c939dcd2ee1480c14 | |
| parent | 9791560c9419a12248b2fe06aff24cf16334b238 (diff) | |
rk3399-puma.dts: reduce sd card max-frequency to 40MHz.
CRC errors (code -84 EILSEQ) have been observed for some SanDisk
Ultra A1 cards when running at 50MHz.
Waveform analysis suggest that the level shifters that are used on the
RK3399-Q7 module for voltage translation between 3.0 and 3.3V don't
handle clock rates at or above 48MHz properly. Back off to 40MHz for
some safety margin.
Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
| -rw-r--r-- | arch/arm64/boot/dts/rockchip/rk3399-puma.dts | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma.dts b/arch/arm64/boot/dts/rockchip/rk3399-puma.dts index 58f91de211cd..d2304dd611de 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399-puma.dts +++ b/arch/arm64/boot/dts/rockchip/rk3399-puma.dts @@ -695,7 +695,7 @@ &sdmmc { // On the AP6255 Wifi module, firmware download fails above 25 MHz. Set to 10 MHz to be safe. //max-frequency = <10000000>; - max-frequency = <50000000>; // 50 MHz = High Speed 3.3V + max-frequency = <40000000>; supports-sdio; supports-sd; bus-width = <4>; |