From 22bc7e38f151c2a010084ce1813daecd5ff66390 Mon Sep 17 00:00:00 2001 From: Can Guo Date: Wed, 13 Jan 2021 19:13:27 -0800 Subject: [PATCH] BACKPORT: FROMGIT: scsi: ufs: Fix a possible NULL pointer issue During system resume/suspend, hba could be NULL. In this case, do not touch eh_sem. Fixes: 88a92d6ae4fe ("scsi: ufs: Serialize eh_work with system PM events and async scan") Link: https://lore.kernel.org/r/1610594010-7254-2-git-send-email-cang@codeaurora.org Acked-by: Stanley Chu Signed-off-by: Can Guo Signed-off-by: Martin K. Petersen Bug: 189457922 (cherry picked from commit fb7afe24ba1b7e27483be7d2ac3ed002e67eecd5 git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git 5.14/scsi-queue) [Can Guo: Resolved minor conflict in ufshcd.c] Change-Id: I7c2cfaf95b8e24529929377096b882cad4fe3c35 Signed-off-by: Can Guo --- drivers/scsi/ufs/ufshcd.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 73cac1a16ad0..7bd5c36e0988 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -98,6 +98,8 @@ 16, 4, buf, __len, false); \ } while (0) +static bool early_suspend; + int ufshcd_dump_regs(struct ufs_hba *hba, size_t offset, size_t len, const char *prefix) { @@ -8907,8 +8909,14 @@ int ufshcd_system_suspend(struct ufs_hba *hba) int ret = 0; ktime_t start = ktime_get(); + if (!hba) { + early_suspend = true; + return 0; + } + down(&hba->eh_sem); - if (!hba || !hba->is_powered) + + if (!hba->is_powered) return 0; cancel_delayed_work_sync(&hba->rpm_dev_flush_recheck_work); @@ -8960,9 +8968,12 @@ int ufshcd_system_resume(struct ufs_hba *hba) int ret = 0; ktime_t start = ktime_get(); - if (!hba) { - up(&hba->eh_sem); + if (!hba) return -EINVAL; + + if (unlikely(early_suspend)) { + early_suspend = false; + down(&hba->eh_sem); } if (!hba->is_powered || pm_runtime_suspended(hba->dev))