| Message ID | 20200608084458.32014-1-narmstrong@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: meson-gx: limit segments to 1 when dram-access-quirk is needed | expand |
Neil Armstrong <narmstrong@baylibre.com> writes: > 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 <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>
On Mon, 8 Jun 2020 at 10:45, Neil Armstrong <narmstrong@baylibre.com> 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 <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> Applied for fixes and by adding a stable tag, thanks! Kind regards Uffe > --- > 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 >
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 /
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 <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> --- drivers/mmc/host/meson-gx-mmc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)