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Commit 06c1a121 authored by Ulf Hansson's avatar Ulf Hansson Committed by Russell King
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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: default avatarUlf Hansson <ulf.hansson@linaro.org>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Acked-by: default avatarJohan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent ddffeb8c

drivers/mmc/host/mmci.c

+21 −17
Original line number Diff line number Diff line
@@ -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