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: Bart Van Assche <bvanassche@xxxxxxx>
Fixes: cc52e15397cc ("scsi: ufs: ufs-exynos: Support ExynosAuto v9 UFS")
Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
Cc: Chanho Park <chanho61.park@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/ufs/host/ufs-exynos.c | 17 +++++++++++++----
drivers/ufs/host/ufs-exynos.h | 3 ++-
2 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c
index f393d42a659f821225e67e3e5d323478456ca3af..61b03e493cc1ddba17179a9f22e5b59ece02458b 100644
--- a/drivers/ufs/host/ufs-exynos.c
+++ b/drivers/ufs/host/ufs-exynos.c
@@ -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;
diff --git a/drivers/ufs/host/ufs-exynos.h b/drivers/ufs/host/ufs-exynos.h
index 17696b3768debd641188b5089585b6d303de7451..a345809af79dc528ad518d3572fe8be034341ee0 100644
--- a/drivers/ufs/host/ufs-exynos.h
+++ b/drivers/ufs/host/ufs-exynos.h
@@ -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)
--
2.49.0.rc1.451.g8f38331e32-goog
