From 753ca4b5beff8fbc4ffce9ba3c54e3d3f63b16f6 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Sun, 9 Nov 2025 19:47:48 -0500 Subject: [PATCH] scsi: ufs: core: Add a quirk for handling broken LSDBS field in controller capabilities register [ Upstream commit cd06b713a6880997ca5aecac8e33d5f9c541749e ] 'Legacy Queue & Single Doorbell Support (LSDBS)' field in the controller capabilities register is supposed to report whether the legacy single doorbell mode is supported in the controller or not. But some controllers report '1' in this field which corresponds to 'LSDB not supported', but they indeed support LSDB. So let's add a quirk to handle those controllers. If the quirk is enabled by the controller driver, then LSDBS register field will be ignored and legacy single doorbell mode is assumed to be enabled always. Tested-by: Amit Pundir Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20240816-ufs-bug-fix-v3-1-e6fe0e18e2a3@linaro.org Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen Stable-dep-of: d968e99488c4 ("scsi: ufs: ufs-pci: Set UFSHCD_QUIRK_PERFORM_LINK_STARTUP_ONCE for Intel ADL") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/ufs/core/ufshcd.c | 6 +++++- include/ufs/ufshcd.h | 8 ++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 18d89567ac14..a834bcd3387b 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -2368,7 +2368,11 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba) * 0h: legacy single doorbell support is available * 1h: indicate that legacy single doorbell support has been removed */ - hba->lsdb_sup = !FIELD_GET(MASK_LSDB_SUPPORT, hba->capabilities); + if (!(hba->quirks & UFSHCD_QUIRK_BROKEN_LSDBS_CAP)) + hba->lsdb_sup = !FIELD_GET(MASK_LSDB_SUPPORT, hba->capabilities); + else + hba->lsdb_sup = true; + if (!hba->mcq_sup) return 0; diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h index 515b9ca5c54f..c2b29fff4765 100644 --- a/include/ufs/ufshcd.h +++ b/include/ufs/ufshcd.h @@ -670,6 +670,14 @@ enum ufshcd_quirks { * the standard best practice for managing keys). */ UFSHCD_QUIRK_KEYS_IN_PRDT = 1 << 24, + + /* + * This quirk indicates that the controller reports the value 1 (not + * supported) in the Legacy Single DoorBell Support (LSDBS) bit of the + * Controller Capabilities register although it supports the legacy + * single doorbell mode. + */ + UFSHCD_QUIRK_BROKEN_LSDBS_CAP = 1 << 25, }; enum ufshcd_caps {