On Google gs101, the number of UTP transfer request slots (nutrs) is 32, and in this case the driver ends up programming the UTRL_NEXUS_TYPE incorrectly as 0.
This is because the left hand side of the shift is 1, which is of type int, i.e. 31 bits wide. Shifting by more than that width results in undefined behaviour.
Fix this by switching to the BIT() macro, which applies correct type casting as required. This ensures the correct value is written to UTRL_NEXUS_TYPE (0xffffffff on gs101), and it also fixes a UBSAN shift warning: UBSAN: shift-out-of-bounds in drivers/ufs/host/ufs-exynos.c:1113:21 shift exponent 32 is too large for 32-bit type 'int'
For consistency, apply the same change to the nutmrs / UTMRL_NEXUS_TYPE write.
Fixes: 55f4b1f73631 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs") Cc: stable@vger.kernel.org Signed-off-by: André Draszik andre.draszik@linaro.org --- drivers/ufs/host/ufs-exynos.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c index 3e545af536e53e06b66c624ed0dc6dc7de13549f..f0adcd9dd553d2e630c75e8c3220e21bc5f7c8d8 100644 --- a/drivers/ufs/host/ufs-exynos.c +++ b/drivers/ufs/host/ufs-exynos.c @@ -1110,8 +1110,8 @@ static int exynos_ufs_post_link(struct ufs_hba *hba) hci_writel(ufs, val, HCI_TXPRDT_ENTRY_SIZE);
hci_writel(ufs, ilog2(DATA_UNIT_SIZE), HCI_RXPRDT_ENTRY_SIZE); - hci_writel(ufs, (1 << hba->nutrs) - 1, HCI_UTRL_NEXUS_TYPE); - hci_writel(ufs, (1 << hba->nutmrs) - 1, HCI_UTMRL_NEXUS_TYPE); + hci_writel(ufs, BIT(hba->nutrs) - 1, HCI_UTRL_NEXUS_TYPE); + hci_writel(ufs, BIT(hba->nutmrs) - 1, HCI_UTMRL_NEXUS_TYPE); hci_writel(ufs, 0xf, HCI_AXIDMA_RWDATA_BURST_LEN);
if (ufs->opts & EXYNOS_UFS_OPT_SKIP_CONNECTION_ESTAB)
--- base-commit: 50c8770a42faf8b1c7abe93e7c114337f580a97d change-id: 20250707-ufs-exynos-shift-b6d1084e28c4
Best regards,
On 7/7/25 10:05 AM, André Draszik wrote:
On Google gs101, the number of UTP transfer request slots (nutrs) is 32, and in this case the driver ends up programming the UTRL_NEXUS_TYPE incorrectly as 0.
This is because the left hand side of the shift is 1, which is of type int, i.e. 31 bits wide. Shifting by more than that width results in undefined behaviour.
Fix this by switching to the BIT() macro, which applies correct type casting as required. This ensures the correct value is written to UTRL_NEXUS_TYPE (0xffffffff on gs101), and it also fixes a UBSAN shift warning: UBSAN: shift-out-of-bounds in drivers/ufs/host/ufs-exynos.c:1113:21 shift exponent 32 is too large for 32-bit type 'int'
For consistency, apply the same change to the nutmrs / UTMRL_NEXUS_TYPE write.
Fixes: 55f4b1f73631 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs") Cc: stable@vger.kernel.org Signed-off-by: André Draszik andre.draszik@linaro.org
drivers/ufs/host/ufs-exynos.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c index 3e545af536e53e06b66c624ed0dc6dc7de13549f..f0adcd9dd553d2e630c75e8c3220e21bc5f7c8d8 100644 --- a/drivers/ufs/host/ufs-exynos.c +++ b/drivers/ufs/host/ufs-exynos.c @@ -1110,8 +1110,8 @@ static int exynos_ufs_post_link(struct ufs_hba *hba) hci_writel(ufs, val, HCI_TXPRDT_ENTRY_SIZE); hci_writel(ufs, ilog2(DATA_UNIT_SIZE), HCI_RXPRDT_ENTRY_SIZE);
- hci_writel(ufs, (1 << hba->nutrs) - 1, HCI_UTRL_NEXUS_TYPE);
- hci_writel(ufs, (1 << hba->nutmrs) - 1, HCI_UTMRL_NEXUS_TYPE);
- hci_writel(ufs, BIT(hba->nutrs) - 1, HCI_UTRL_NEXUS_TYPE);
- hci_writel(ufs, BIT(hba->nutmrs) - 1, HCI_UTMRL_NEXUS_TYPE); hci_writel(ufs, 0xf, HCI_AXIDMA_RWDATA_BURST_LEN);
if (ufs->opts & EXYNOS_UFS_OPT_SKIP_CONNECTION_ESTAB)
Reviewed-by: Bart Van Assche bvanassche@acm.org
On Mon, 7 Jul 2025 at 18:05, André Draszik andre.draszik@linaro.org wrote:
On Google gs101, the number of UTP transfer request slots (nutrs) is 32, and in this case the driver ends up programming the UTRL_NEXUS_TYPE incorrectly as 0.
This is because the left hand side of the shift is 1, which is of type int, i.e. 31 bits wide. Shifting by more than that width results in undefined behaviour.
Fix this by switching to the BIT() macro, which applies correct type casting as required. This ensures the correct value is written to UTRL_NEXUS_TYPE (0xffffffff on gs101), and it also fixes a UBSAN shift warning: UBSAN: shift-out-of-bounds in drivers/ufs/host/ufs-exynos.c:1113:21 shift exponent 32 is too large for 32-bit type 'int'
For consistency, apply the same change to the nutmrs / UTMRL_NEXUS_TYPE write.
Fixes: 55f4b1f73631 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs") Cc: stable@vger.kernel.org Signed-off-by: André Draszik andre.draszik@linaro.org
Reviewed-by: Peter Griffin peter.griffin@linaro.org
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