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[v3,2/2] ufs: qcom: Add UFSHCD_QUIRK_BROKEN_LSDBS_CAP for SM8550 SoC

Message ID 20240816-ufs-bug-fix-v3-2-e6fe0e18e2a3@linaro.org
State New
Headers show
Series ufs: qcom: Fix probe failure on SM8550 SoC due to broken LSDBS field | expand

Commit Message

Manivannan Sadhasivam via B4 Relay Aug. 16, 2024, 6:25 a.m. UTC 
From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

SM8550 SoC has the UFSHCI 4.0 compliant UFS controller and only supports
legacy single doorbell mode without MCQ. But due to a hardware bug, it
reports 1 in the 'Legacy Queue & Single Doorbell Support (LSDBS)' field of
the Controller Capabilities register. This field is supposed to read as 0
if legacy single doorbell mode is supported and 1 otherwise.

Starting with commit 0c60eb0cc320 ("scsi: ufs: core: Check LSDBS cap when
!mcq"), ufshcd driver is now relying on the LSDBS field to decide when to
use the legacy doorbell mode if MCQ is not supported. And this ends up
breaking UFS on SM8550:

ufshcd-qcom 1d84000.ufs: ufshcd_init: failed to initialize (legacy doorbell mode not supported)
ufshcd-qcom 1d84000.ufs: error -EINVAL: Initialization failed with error -22

So use the UFSHCD_QUIRK_BROKEN_LSDBS_CAP quirk for SM8550 SoC so that the
ufshcd driver could use legacy doorbell mode correctly.

Fixes: 0c60eb0cc320 ("scsi: ufs: core: Check LSDBS cap when !mcq")
Tested-by: Amit Pundir <amit.pundir@linaro.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/ufs/host/ufs-qcom.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
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Patch

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 810e637047d0..c87fdc849c62 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -857,6 +857,9 @@  static void ufs_qcom_advertise_quirks(struct ufs_hba *hba)
 
 	if (host->hw_ver.major > 0x3)
 		hba->quirks |= UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH;
+
+	if (of_device_is_compatible(hba->dev->of_node, "qcom,sm8550-ufshc"))
+		hba->quirks |= UFSHCD_QUIRK_BROKEN_LSDBS_CAP;
 }
 
 static void ufs_qcom_set_phy_gear(struct ufs_qcom_host *host)
@@ -1847,7 +1850,8 @@  static void ufs_qcom_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id ufs_qcom_of_match[] __maybe_unused = {
-	{ .compatible = "qcom,ufshc"},
+	{ .compatible = "qcom,ufshc" },
+	{ .compatible = "qcom,sm8550-ufshc" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ufs_qcom_of_match);