diff options
| author | Stefan Nilsson XK <stefan.xk.nilsson@stericsson.com> | 2010-11-25 15:38:02 +0100 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@stericsson.com> | 2011-09-19 16:07:35 +0200 |
| commit | 218b21b2d99be8a7559fa221176a68750afffc07 (patch) | |
| tree | f8bac7062b0622014c261e355e713f0f8c73f1a3 /drivers/mmc | |
| parent | d1932c84b4475b46dc6bcb1f8b43bc4c9d84a931 (diff) | |
MMCI: Fix incorrect handling of HW FC for SDIO
For SDIO writes smaller than or equal to 8 bytes (only SDIO case),
hardware flow control was turned off, but was never turned on again
which meant that if a large read request followed, SDIO would randomly
give buffer overrun errors since there was no flow control.
Since HW flow control is not really needed for anything that fits in the
HW FIFO of PL18X, HW flow control is now disabled for any write
operation that is smaller than or equal to the FIFO size.
ST-Ericsson ID: ER280840
ST-Ericsson FOSS-OUT ID: Trivial
Change-Id: I9c47315dbc4b45011d89b1e58605056ba5441db1
Signed-off-by: Stefan Nilsson XK <stefan.xk.nilsson@stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/9447
Reviewed-by: Ulf HANSSON <ulf.hansson@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/10931
Reviewed-by: QATOOLS
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/30928
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/mmci.c | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index cea09e265a2..fe783a470e9 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -604,9 +604,32 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) /* The ST Micro variants has a special bit to enable SDIO */ if (variant->sdio && host->mmc->card) - if (mmc_card_sdio(host->mmc->card)) + if (mmc_card_sdio(host->mmc->card)) { + /* + * The ST Micro variants has a special bit + * to enable SDIO. + */ datactrl |= MCI_ST_DPSM_SDIOEN; + /* + * The ST Micro variant for SDIO transfer sizes + * less then or equal to 8 bytes needs to have clock + * H/W flow control disabled. Since flow control is + * not really needed for anything that fits in the + * FIFO, we can disable it for any write smaller + * than the FIFO size. + */ + if ((host->size <= variant->fifosize) && + (data->flags & MMC_DATA_WRITE)) + writel(readl(host->base + MMCICLOCK) & + ~variant->clkreg_enable, + host->base + MMCICLOCK); + else + writel(readl(host->base + MMCICLOCK) | + variant->clkreg_enable, + host->base + MMCICLOCK); + } + /* * Attempt to use DMA operation mode, if this * should fail, fall back to PIO mode @@ -822,23 +845,6 @@ static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int rem count = min(remain, maxcnt); /* - * The ST Micro variant for SDIO transfer sizes - * less then 8 bytes should have clock H/W flow - * control disabled. - */ - if (variant->sdio && - mmc_card_sdio(host->mmc->card)) { - if (count < 8) - writel(readl(host->base + MMCICLOCK) & - ~variant->clkreg_enable, - host->base + MMCICLOCK); - else - writel(readl(host->base + MMCICLOCK) | - variant->clkreg_enable, - host->base + MMCICLOCK); - } - - /* * SDIO especially may want to send something that is * not divisible by 4 (as opposed to card sectors * etc), and the FIFO only accept full 32-bit writes. |