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ARM: 7551/1: mmc: mmci: Fix incorrect handling of HW flow control for SDIO

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For data writes <= 8 bytes, HW flow control was disabled but
never re-enabled when the transfer was completed. This meant
that a following read request would give buffer overrun errors.

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>
This commit is contained in:
Ulf Hansson 2012-10-12 14:01:50 +01:00 • committed by Russell King
parent ddffeb8c4d
commit 06c1a12180
1 changed files with 21 additions and 17 deletions
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38
drivers/mmc/host/mmci.c
View file

@ -654,9 +654,29 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
/* The ST Micro variants has a special bit to enable SDIO */ /* The ST Micro variants has a special bit to enable SDIO */
if (variant->sdio && host->mmc->card) 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.
*/
u32 clk;
datactrl |= MCI_ST_DPSM_SDIOEN; 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.
*/
if ((host->size < 8) &&
(data->flags & MMC_DATA_WRITE))
clk = host->clk_reg & ~variant->clkreg_enable;
else
clk = host->clk_reg | variant->clkreg_enable;
mmci_write_clkreg(host, clk);
}
/* /*
* Attempt to use DMA operation mode, if this * Attempt to use DMA operation mode, if this
* should fail, fall back to PIO mode * should fail, fall back to PIO mode
@ -876,22 +896,6 @@ static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int rem
variant->fifosize : variant->fifohalfsize; variant->fifosize : variant->fifohalfsize;
count = min(remain, maxcnt); 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)) {
u32 clk;
if (count < 8)
clk = host->clk_reg & ~variant->clkreg_enable;
else
clk = host->clk_reg | variant->clkreg_enable;
mmci_write_clkreg(host, clk);
}
/* /*
* SDIO especially may want to send something that is * SDIO especially may want to send something that is
* not divisible by 4 (as opposed to card sectors * not divisible by 4 (as opposed to card sectors