linux/drivers/mmc
Martin Blumenstingl c70805dca1 mmc: meson-mx-sdhc: Fix manual RX FIFO flushing
For Meson8 and Meson8b SoCs the vendor driver follows the following
pattern:
- for eMMC and SD cards in .set_pdma it sets:
  pdma->rxfifo_manual_flush = 1;
- for SDIO cards in .set_pdma it sets:
  pdma->rxfifo_manual_flush = 0;
- before syncing the DMA read buffer is sets:
  pdma->rxfifo_manual_flush |= 0x02;

Set the second bit of MESON_SDHC_PDMA_RXFIFO_MANUAL_FLUSH without
clearing the first bit before syncing the DMA read buffer. This fixes a
problem where Meson8 and Meson8b SoCs would read random garbage from SD
cards. It is not clear why it worked for eMMC cards. This manifested in
the following errors when plugging in an SD card:
  unrecognised SCR structure version <random number>

Cc: Thomas Graichen <thomas.graichen@gmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20200517222907.1277787-1-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2020-05-28 11:22:15 +02:00
..
core mmc: core: Enable erase/discard/trim support for all mmc hosts 2020-05-28 11:22:14 +02:00
host mmc: meson-mx-sdhc: Fix manual RX FIFO flushing 2020-05-28 11:22:15 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00