This is a note to let you know that I've just added the patch titled mmc: meson-gx: limit segments to 1 when dram-access-quirk is needed to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-meson-gx-limit-segments-to-1-when-dram-access-quirk-is-needed.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 27a5e7d36d383970affae801d77141deafd536a8 Mon Sep 17 00:00:00 2001 From: Neil Armstrong <narmstrong@xxxxxxxxxxxx> Date: Mon, 8 Jun 2020 10:44:58 +0200 Subject: mmc: meson-gx: limit segments to 1 when dram-access-quirk is needed From: Neil Armstrong <narmstrong@xxxxxxxxxxxx> 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@xxxxxxxxxx> Reported-by: Christian Hewitt <christianshewitt@xxxxxxxxx> Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk") Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx> Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20200608084458.32014-1-narmstrong@xxxxxxxxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -1151,9 +1151,11 @@ 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 / Patches currently in stable-queue which might be from narmstrong@xxxxxxxxxxxx are queue-5.4/mmc-meson-gx-limit-segments-to-1-when-dram-access-quirk-is-needed.patch