Re: [PATCH] mmc: meson-gx: limit segments to 1 when dram-access-quirk is needed
From: Ulf Hansson <hidden>
Date: 2020-06-16 11:33:25
Also in:
linux-amlogic, linux-mmc, lkml
On Mon, 8 Jun 2020 at 10:45, Neil Armstrong [off-list ref] wrote:
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 functionnality with the brcmfmac/bcmsdh driver on Amlogic
G12A/G12B SoCs on boards like SEI510 or Khadas VIM3.
Reported-by: Art Nikpal <redacted>
Reported-by: Christian Hewitt <redacted>
Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk")
Signed-off-by: Neil Armstrong <redacted>Applied for fixes and by adding a stable tag, thanks! Kind regards Uffe
quoted hunk ↗ jump to hunk
--- drivers/mmc/host/meson-gx-mmc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index 35400cf2a2e4..cfaf8e7e22ec 100644 --- 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 platform_device *pdev) 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 / --2.22.0
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