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From:   Arnd Bergmann <arnd@kernel.org>
To:     Stanley Chu <stanley.chu@mediatek.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Bean Huo <beanhuo@micron.com>,
        Peter Wang <peter.wang@mediatek.com>,
        Bart Van Assche <bvanassche@acm.org>,
        linux-scsi@vger.kernel.org, linux-mediatek@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: [PATCH] scsi: ufs: mediatek: avoid sched_clock() misuse
Date:   Mon, 18 Oct 2021 15:20:01 +0200
Message-Id: <20211018132022.2281589-1-arnd@kernel.org>
MIME-Version: 1.0
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From: Arnd Bergmann <arnd@arndb.de>

sched_clock() is not meant to be used in portable driver code,
and assuming a particular clock frequency is not how this is
meant to be used. It also causes a build failure because of
a missing header inclusion:

drivers/scsi/ufs/ufs-mediatek.c:321:12: error: implicit declaration of function 'sched_clock' [-Werror,-Wimplicit-function-declaration]
        timeout = sched_clock() + retry_ms * 1000000UL;

A better interface to use here ktime_get_mono_fast_ns(), which
works mostly like ktime_get() but is safe to use inside of a
suspend callback.

Fixes: 9561f58442e4 ("scsi: ufs: mediatek: Support vops pre suspend to disable auto-hibern8")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/scsi/ufs/ufs-mediatek.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index d1696db70ce8..a47241ed0a57 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -318,15 +318,15 @@ static void ufs_mtk_wait_idle_state(struct ufs_hba *hba,
 	u32 val, sm;
 	bool wait_idle;
 
-	timeout = sched_clock() + retry_ms * 1000000UL;
-
+	/* cannot use plain ktime_get() in suspend */
+	timeout = ktime_get_mono_fast_ns() + retry_ms * 1000000UL;
 
 	/* wait a specific time after check base */
 	udelay(10);
 	wait_idle = false;
 
 	do {
-		time_checked = sched_clock();
+		time_checked = ktime_get_mono_fast_ns();
 		ufs_mtk_dbg_sel(hba);
 		val = ufshcd_readl(hba, REG_UFS_PROBE);
 
-- 
2.29.2