From 06c1a121805d7870abbf037d3ccd9a609a5219f2 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Fri, 12 Oct 2012 14:01:50 +0100 Subject: [PATCH] ARM: 7551/1: mmc: mmci: Fix incorrect handling of HW flow control for SDIO 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 Acked-by: Linus Walleij Acked-by: Johan Rudholm Signed-off-by: Russell King --- drivers/mmc/host/mmci.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-) diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index edc3e9baf0e7..877079e778cd 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -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 */ 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; + /* + * 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 * 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; 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 * not divisible by 4 (as opposed to card sectors -- 2.20.1