-----Original Message----- From: Adam Ford [mailto:aford173@gmail.com] Sent: 2022年1月12日 21:54 To: u-boot@lists.denx.de Cc: Peng Fan peng.fan@nxp.com; Bough Chen haibo.chen@nxp.com; andrey.zhizhikin@leica-geosystems.com; tharvey@gateworks.com; estevam@gmail.com; sbabic@denx.de; aford@beaconembedded.com; Adam Ford aford173@gmail.com Subject: [PATCH 1/2] mmc: fsl_esdhc_imx: Fix fsl_esdhc_wait_dat0
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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.de nx.de%2Fpipermail%2Fu-boot%2F2021-January%2F438644.html&data=04 %7C01%7Chaibo.chen%40nxp.com%7C5de948ddd6fb41a9ab2c08d9d5d304d9 %7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63777592456049525 1%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiL CJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=QVXYNWR3t2N9oCr BZSnoJVquwWdJuvo0hmuP%2FZhZifc%3D&reserved=0
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);
Hi Adam,
For the usdhc on i.MX, the bit VENDORSPEC_CKEN is not implement by IP, instead, we use the bit 8 of register 0xc0.
By the way, for the wait_dat0 function, it not only cover the IO voltage switch process, other place also need this function. So I think this change is not correct.
Best Regards Haibo Chen
ret = readx_poll_timeout(esdhc_read32, ®s->prsstat, tmp,
!!(tmp & PRSSTAT_DAT0) == !!state,
(tmp & PRSSTAT_SDSTB), timeout_us);- return ret;
}
-- 2.32.0