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Commit 70ac0935 authored by Ulf Hansson's avatar Ulf Hansson Committed by Russell King
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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: 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 06c1a121

drivers/mmc/host/mmci.c

+7 −5
Original line number Diff line number Diff line
@@ -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;