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Commit 5f651b87 authored by Corneliu Doban's avatar Corneliu Doban Committed by Ulf Hansson
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mmc: sdhci-iproc: fix 32bit writes for TRANSFER_MODE register 



When the host controller accepts only 32bit writes, the value of the
16bit TRANSFER_MODE register, that has the same 32bit address as the
16bit COMMAND register, needs to be saved and it will be written
in a 32bit write together with the command as this will trigger the
host to send the command on the SD interface.
When sending the tuning command, TRANSFER_MODE is written and then
sdhci_set_transfer_mode reads it back to clear AUTO_CMD12 bit and
write it again resulting in wrong value to be written because the
initial write value was saved in a shadow and the read-back returned
a wrong value, from the register.
Fix sdhci_iproc_readw to return the saved value of TRANSFER_MODE
when a saved value exist.
Same fix for read of BLOCK_SIZE and BLOCK_COUNT registers, that are
saved for a different reason, although a scenario that will cause the
mentioned problem on this registers is not probable.

Fixes: b580c52d ("mmc: sdhci-iproc: add IPROC SDHCI driver")
Signed-off-by: default avatarCorneliu Doban <corneliu.doban@broadcom.com>
Signed-off-by: default avatarScott Branden <scott.branden@broadcom.com>
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 4c94238f

drivers/mmc/host/sdhci-iproc.c

+25 −5
Original line number Diff line number Diff line
@@ -33,6 +33,8 @@ struct sdhci_iproc_host { 
	const struct sdhci_iproc_data *data;

	u32 shadow_cmd;

	u32 shadow_blk;

	bool is_cmd_shadowed;

	bool is_blk_shadowed;

};



#define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18)
@@ -48,8 +50,22 @@ static inline u32 sdhci_iproc_readl(struct sdhci_host *host, int reg) 


static u16 sdhci_iproc_readw(struct sdhci_host *host, int reg)

{

	u32 val = sdhci_iproc_readl(host, (reg & ~3));

	u16 word = val >> REG_OFFSET_IN_BITS(reg) & 0xffff;

	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);

	struct sdhci_iproc_host *iproc_host = sdhci_pltfm_priv(pltfm_host);

	u32 val;

	u16 word;



	if ((reg == SDHCI_TRANSFER_MODE) && iproc_host->is_cmd_shadowed) {

		/* Get the saved transfer mode */

		val = iproc_host->shadow_cmd;

	} else if ((reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) &&

		   iproc_host->is_blk_shadowed) {

		/* Get the saved block info */

		val = iproc_host->shadow_blk;

	} else {

		val = sdhci_iproc_readl(host, (reg & ~3));

	}

	word = val >> REG_OFFSET_IN_BITS(reg) & 0xffff;

	return word;

}
@@ -105,13 +121,15 @@ static void sdhci_iproc_writew(struct sdhci_host *host, u16 val, int reg) 


	if (reg == SDHCI_COMMAND) {

		/* Write the block now as we are issuing a command */

		if (iproc_host->shadow_blk != 0) {

		if (iproc_host->is_blk_shadowed) {

			sdhci_iproc_writel(host, iproc_host->shadow_blk,

				SDHCI_BLOCK_SIZE);

			iproc_host->shadow_blk = 0;

			iproc_host->is_blk_shadowed = false;

		}

		oldval = iproc_host->shadow_cmd;

	} else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {

		iproc_host->is_cmd_shadowed = false;

	} else if ((reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) &&

		   iproc_host->is_blk_shadowed) {

		/* Block size and count are stored in shadow reg */

		oldval = iproc_host->shadow_blk;

	} else {
@@ -123,9 +141,11 @@ static void sdhci_iproc_writew(struct sdhci_host *host, u16 val, int reg) 
	if (reg == SDHCI_TRANSFER_MODE) {

		/* Save the transfer mode until the command is issued */

		iproc_host->shadow_cmd = newval;

		iproc_host->is_cmd_shadowed = true;

	} else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {

		/* Save the block info until the command is issued */

		iproc_host->shadow_blk = newval;

		iproc_host->is_blk_shadowed = true;

	} else {

		/* Command or other regular 32-bit write */

		sdhci_iproc_writel(host, newval, reg & ~3);