From 2d122e38020d90a19098ae1097a33b3222fd5e67 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 19 Apr 2022 15:58:03 -0700 Subject: [PATCH] UPSTREAM: scsi: ufs: Remove locking from around single register writes Single register writes are atomic and hence do not need to be surrounded by locking. Additionally, MMIO writes are typically posted asynchronously. Hence, there is no guarantee that these have finished by the time the spin_unlock*() call has finished. See also the nonposted-mmio property of the Open Firmware tree. See also pci_iomap(). Link: https://lore.kernel.org/r/20220419225811.4127248-21-bvanassche@acm.org Tested-by: Bean Huo Reviewed-by: Avri Altman Reviewed-by: Bean Huo Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Bug: 234653003 (cherry picked from commit 3fb20fcd93fe5a1580355f1ea73f6daed1712f06) Change-Id: I50811ddab2c745ac1fe898e83bf7a0cd4e4ce7e4 Signed-off-by: Bart Van Assche --- drivers/scsi/ufs/ufs-mediatek.c | 8 -------- drivers/scsi/ufs/ufshcd.c | 4 ---- 2 files changed, 12 deletions(-) diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c index 9a4474210627..2b26acc74efb 100644 --- a/drivers/scsi/ufs/ufs-mediatek.c +++ b/drivers/scsi/ufs/ufs-mediatek.c @@ -171,7 +171,6 @@ static int ufs_mtk_hce_enable_notify(struct ufs_hba *hba, enum ufs_notify_change_status status) { struct ufs_mtk_host *host = ufshcd_get_variant(hba); - unsigned long flags; if (status == PRE_CHANGE) { if (host->unipro_lpm) { @@ -185,12 +184,8 @@ static int ufs_mtk_hce_enable_notify(struct ufs_hba *hba, ufs_mtk_crypto_enable(hba); if (host->caps & UFS_MTK_CAP_DISABLE_AH8) { - spin_lock_irqsave(hba->host->host_lock, flags); ufshcd_writel(hba, 0, REG_AUTO_HIBERNATE_IDLE_TIMER); - spin_unlock_irqrestore(hba->host->host_lock, - flags); - hba->capabilities &= ~MASK_AUTO_HIBERN8_SUPPORT; hba->ahit = 0; } @@ -994,13 +989,10 @@ static void ufs_mtk_vreg_set_lpm(struct ufs_hba *hba, bool lpm) static void ufs_mtk_auto_hibern8_disable(struct ufs_hba *hba) { - unsigned long flags; int ret; /* disable auto-hibern8 */ - spin_lock_irqsave(hba->host->host_lock, flags); ufshcd_writel(hba, 0, REG_AUTO_HIBERNATE_IDLE_TIMER); - spin_unlock_irqrestore(hba->host->host_lock, flags); /* wait host return to idle state when auto-hibern8 off */ ufs_mtk_wait_idle_state(hba, 5); diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a2ffe84d7056..180fadc5314a 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -4276,14 +4276,10 @@ EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update); void ufshcd_auto_hibern8_enable(struct ufs_hba *hba) { - unsigned long flags; - if (!ufshcd_is_auto_hibern8_supported(hba)) return; - spin_lock_irqsave(hba->host->host_lock, flags); ufshcd_writel(hba, hba->ahit, REG_AUTO_HIBERNATE_IDLE_TIMER); - spin_unlock_irqrestore(hba->host->host_lock, flags); } /**