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Commit f328c76e authored Apr 23, 2017 by jiajie.hao@mediatek.com Committed by Ulf Hansson Apr 24, 2017

mmc: sdio: Fix sdio wait busy implement limitation



The host may issue an I/O abort by writing to the CCCR at any time
during I/O read operation via CMD52. And host may need suspend
transcation during write busy stage in SDIO suspend/resume scenario.
>From other side, a card may accept CMD52 during data transfer phase.

Previous implement would block issuing above command in busy stage.
It cause function driver can't implement as proper way and has no
opportunity to do some coverage in error case via I/O abort etc.

We need bypass some necessary operation during busy check stage.

Signed-off-by: Jiajie Hao <jiajie.hao@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

parent d9370424

drivers/mmc/core/core.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -239,8 +239,10 @@ static void __mmc_start_request(struct mmc_host host, struct mmc_request mrq)
		/*
		* For sdio rw commands we must wait for card busy otherwise some
		* sdio devices won't work properly.
		* And bypass I/O abort, reset and bus suspend operations.
		*/
		if (mmc_is_io_op(mrq->cmd->opcode) && host->ops->card_busy) {
		if (sdio_is_io_busy(mrq->cmd->opcode, mrq->cmd->arg) &&
		host->ops->card_busy) {
		int tries = 500; /* Wait aprox 500ms at maximum */

		while (host->ops->card_busy(host) && --tries)

drivers/mmc/core/sdio_ops.h

+8 −2

Original line number	Diff line number	Diff line
		@@ -26,9 +26,15 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
		int sdio_reset(struct mmc_host *host);
		unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz);

		static inline bool mmc_is_io_op(u32 opcode)
		static inline bool sdio_is_io_busy(u32 opcode, u32 arg)
		{
		return opcode == SD_IO_RW_DIRECT \|\| opcode == SD_IO_RW_EXTENDED;
		u32 addr;

		addr = (arg >> 9) & 0x1FFFF;

		return (opcode == SD_IO_RW_EXTENDED \|\|
		(opcode == SD_IO_RW_DIRECT &&
		!(addr == SDIO_CCCR_ABORT \|\| addr == SDIO_CCCR_SUSPEND)));
		}

		#endif