mmc: sdhci-esdhc-imx: Remove the ENGcm07207 workaround

mmc: sdhci-esdhc-imx: Remove the ENGcm07207 workaround

The SDHCI_QUIRK_NO_MULTIBLOCK quirk was used as a workaround for the
ENGcm07207 erratum. However, it caused excruciatingly slow SD transfers
(300 kB/s on average), and this erratum actually does not imply that
multiple-block transfers are not supported, so this was overkill.

The suggested workaround for this erratum is to set SYSCTL.RSTA, but the
simple DAT line software reset (which resets the DMA circuit among
others) triggered by sdhci_finish_data() in case of errors seems to be
sufficient. Indeed, generating errors in a controlled manner on i.MX25
using the FEVT register right in the middle of read data transfers
without this quirk shows that nothing is written to the buffer by the
eSDHC past CMD12, and no extra Auto CMD12 is sent with AC12EN set, so
the data transfers on AHB are properly aborted. For write data
transfers, neither extra data nor extra Auto CMD12 is sent, as expected.
Moreover, after intensive stress tests on i.MX25, removing
SDHCI_QUIRK_NO_MULTIBLOCK seems to be safe.

SDHCI_QUIRK_BROKEN_ADMA has nothing to do with ENGcm07207, so set
ESDHC_FLAG_ERR004536 for the devices that had ESDHC_FLAG_ENGCM07207 set
in order to continue getting SDHCI_QUIRK_BROKEN_ADMA.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>