diff options
| author | Ulf Hansson <ulf.hansson@linaro.org> | 2012-10-12 15:07:36 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-10-18 12:06:23 +0200 |
| commit | 70ac09358cc52f3ddbf73555dc150d486a7133bb (patch) | |
| tree | 8d210b8a67722192b37b0b7c6b4fa233703efdbf /drivers/mmc | |
| parent | ARM: 7551/1: mmc: mmci: Fix incorrect handling of HW flow control for SDIO (diff) | |
| download | linux-70ac09358cc52f3ddbf73555dc150d486a7133bb.tar.xz linux-70ac09358cc52f3ddbf73555dc150d486a7133bb.zip | |
ARM: 7552/1: mmc: mmci: Switching off HWFC for SDIO depends on MCLK
For writes, HWFC shall be switched off when transfer size <= 8
bytes and when MCLK rate is above 50 MHz. For 50MHz and below
it shall be switched off when transfer size < 8 bytes.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Johan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/mmci.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 877079e778cd..cd0fbee0b1c0 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -664,12 +664,14 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) datactrl |= MCI_ST_DPSM_SDIOEN; /* - * The ST Micro variant for SDIO transfer sizes - * less then 8 bytes should have clock H/W flow - * control disabled. + * The ST Micro variant for SDIO small write transfers + * needs to have clock H/W flow control disabled, + * otherwise the transfer will not start. The threshold + * depends on the rate of MCLK. */ - if ((host->size < 8) && - (data->flags & MMC_DATA_WRITE)) + if (data->flags & MMC_DATA_WRITE && + (host->size < 8 || + (host->size <= 8 && host->mclk > 50000000))) clk = host->clk_reg & ~variant->clkreg_enable; else clk = host->clk_reg | variant->clkreg_enable; |