According to Haibo Chen [1] - the current implementation mmc_wait_dat0, the second mmc_wait_dat0() in mmc_switch_voltage() always return timeout. This causes UHS cards to not properly initialize to their highest rate, and default back for high-speed mode. When reviewing [1] and comparing it to the linux driver, it appears that this function can be accomplished by turning off the clock, and waiting for the clock-standby bit to become active. [1] - https://lists.denx.de/pipermail/u-boot/2021-January/438644.html Reported-by: Tim Harvey tharvey@gateworks.com Signed-off-by: Adam Ford aford173@gmail.com diff --git a/drivers/mmc/fsl_esdhc_imx.c b/drivers/mmc/fsl_esdhc_imx.c index 4c06361bee..e5814232a2 100644 --- a/drivers/mmc/fsl_esdhc_imx.c +++ b/drivers/mmc/fsl_esdhc_imx.c @@ -1684,9 +1684,15 @@ static int fsl_esdhc_wait_dat0(struct udevice *dev, int state, struct fsl_esdhc_priv *priv = dev_get_priv(dev); struct fsl_esdhc *regs = priv->esdhc_regs;
- /*
* Clear the clock-enable and wait for the bit indicating it* is in standby.*/- esdhc_clrbits32(®s->vendorspec, VENDORSPEC_CKEN); ret = readx_poll_timeout(esdhc_read32, ®s->prsstat, tmp,
!!(tmp & PRSSTAT_DAT0) == !!state,
(tmp & PRSSTAT_SDSTB), timeout_us);- return ret;
}
Applied to u-boot-imx, master, thanks !
Best regards, Stefano Babic