In current code, we add 1ms dealy after each tuning command for standard
tuning method. Adding this 1ms dealy is because USDHC default check the
CMD CRC and DATA line. If detect the CMD CRC, USDHC standard tuning
IC logic do not wait for the tuning data sending out by the card, trigger
the buffer read ready interrupt immediately, and step to next cycle. So
when next time the new tuning command send out by USDHC, card may still
not send out the tuning data of the upper command，then some eMMC cards
may stuck, can't response to any command, block the whole tuning procedure.
If do not check the CMD CRC for tuning, then do not has this issue. USDHC
will wait for the tuning data of each tuning command and check them. If the
tuning data pass the check, it also means the CMD line also okay for tuning.
So this patch disable the CMD CRC check for tuning, save some time for the
whole tuning procedure.
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
According the RM, the bit[6~0] of register ESDHC_TUNING_CTRL is
TUNING_START_TAP, bit[7] of this register is to disable the command
CRC check for standard tuning. So fix it here.
Fixes: fa33d20749 ("mmc: split fsl_esdhc driver for i.MX")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
The fsl_esdhc driver was for Freescale eSDHC on MPC83XX/MPC85XX
initially. The later QoriQ series PowerPC processors (which were
evolutions of MPC83XX/MPC85XX), QorIQ series ARM processors, and
i.MX series processors were using this driver for their eSDHCs too.
For the two series processors, the eSDHCs are becoming more and
more different. We should have split it into two drivers, like them
(sdhci-of-esdhc.c/sdhci-esdhc-imx.c) in linux kernel.
This patch is just to create a fsl_esdhc_imx driver which is a copy
of fsl_esdhc driver for i.MX processors. We will convert i.MX processors
to use fsl_esdhc_imx, and clean up the two drivers separately in the
future patches.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Tested-by: Steffen Dirkwinkel <s.dirkwinkel@beckhoff.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Martyn Welch <martyn.welch@collabora.com>
