From: Neil Armstrong narmstrong@baylibre.com
commit 27a5e7d36d383970affae801d77141deafd536a8 upstream.
The actual max_segs computation leads to failure while using the broadcom sdio brcmfmac/bcmsdh driver, since the driver tries to make usage of scatter gather.
But with the dram-access-quirk we use a 1,5K SRAM bounce buffer, and the max_segs current value of 3 leads to max transfers to 4,5k, which doesn't work.
This patch sets max_segs to 1 to better describe the hardware limitation, and fix the SDIO functionality with the brcmfmac/bcmsdh driver on Amlogic G12A/G12B SoCs on boards like SEI510 or Khadas VIM3.
Reported-by: Art Nikpal art@khadas.com Reported-by: Christian Hewitt christianshewitt@gmail.com Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk") Signed-off-by: Neil Armstrong narmstrong@baylibre.com Reviewed-by: Kevin Hilman khilman@baylibre.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200608084458.32014-1-narmstrong@baylibre.com Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/host/meson-gx-mmc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -1143,9 +1143,11 @@ static int meson_mmc_probe(struct platfo
mmc->caps |= MMC_CAP_CMD23; if (host->dram_access_quirk) { + /* Limit segments to 1 due to low available sram memory */ + mmc->max_segs = 1; /* Limit to the available sram memory */ - mmc->max_segs = SD_EMMC_SRAM_DATA_BUF_LEN / mmc->max_blk_size; - mmc->max_blk_count = mmc->max_segs; + mmc->max_blk_count = SD_EMMC_SRAM_DATA_BUF_LEN / + mmc->max_blk_size; } else { mmc->max_blk_count = CMD_CFG_LENGTH_MASK; mmc->max_segs = SD_EMMC_DESC_BUF_LEN /