Commit f92bb743 authored by Peter Griffin's avatar Peter Griffin Committed by Martin K. Petersen
Browse files

scsi: ufs: exynos: Disable iocc if dma-coherent property isn't set 



If dma-coherent property isn't set then descriptors are non-cacheable
and the iocc shareability bits should be disabled. Without this UFS can
end up in an incompatible configuration and suffer from random cache
related stability issues.

Suggested-by: default avatarBart Van Assche <bvanassche@acm.org>
Fixes: cc52e153 ("scsi: ufs: ufs-exynos: Support ExynosAuto v9 UFS")
Signed-off-by: default avatarPeter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20250319-exynos-ufs-stability-fixes-v2-3-96722cc2ba1b@linaro.org


Cc: Chanho Park <chanho61.park@samsung.com>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 68f5ef7e

drivers/ufs/host/ufs-exynos.c

+13 −4
Original line number Diff line number Diff line
@@ -214,8 +214,8 @@ static int exynos_ufs_shareability(struct exynos_ufs *ufs) 
	/* IO Coherency setting */

	if (ufs->sysreg) {

		return regmap_update_bits(ufs->sysreg,

					  ufs->shareability_reg_offset,

					  ufs->iocc_mask, ufs->iocc_mask);

					  ufs->iocc_offset,

					  ufs->iocc_mask, ufs->iocc_val);

	}



	return 0;
@@ -1173,13 +1173,22 @@ static int exynos_ufs_parse_dt(struct device *dev, struct exynos_ufs *ufs) 
		ufs->sysreg = NULL;

	else {

		if (of_property_read_u32_index(np, "samsung,sysreg", 1,

					       &ufs->shareability_reg_offset)) {

					       &ufs->iocc_offset)) {

			dev_warn(dev, "can't get an offset from sysreg. Set to default value\n");

			ufs->shareability_reg_offset = UFS_SHAREABILITY_OFFSET;

			ufs->iocc_offset = UFS_SHAREABILITY_OFFSET;

		}

	}



	ufs->iocc_mask = ufs->drv_data->iocc_mask;

	/*

	 * no 'dma-coherent' property means the descriptors are

	 * non-cacheable so iocc shareability should be disabled.

	 */

	if (of_dma_is_coherent(dev->of_node))

		ufs->iocc_val = ufs->iocc_mask;

	else

		ufs->iocc_val = 0;



	ufs->pclk_avail_min = PCLK_AVAIL_MIN;

	ufs->pclk_avail_max = PCLK_AVAIL_MAX;

drivers/ufs/host/ufs-exynos.h

+2 −1
Original line number Diff line number Diff line
@@ -231,8 +231,9 @@ struct exynos_ufs { 
	ktime_t entry_hibern8_t;

	const struct exynos_ufs_drv_data *drv_data;

	struct regmap *sysreg;

	u32 shareability_reg_offset;

	u32 iocc_offset;

	u32 iocc_mask;

	u32 iocc_val;



	u32 opts;

#define EXYNOS_UFS_OPT_HAS_APB_CLK_CTRL		BIT(0)