From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=203.254.224.33 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793852447; b=EIHsA6DR3SoCjxE2r533+5oeWOtKm2wIIVvwMKmMKlMTWQDTD03LI8Fa/xH0+2VfwmIH zDNUXgsLCtMKLvKqw45mKZc7pz693nRynZS2edGG5sV5TmEhetK+FQfiBZo+MOun+jLrw wzXK4Yc4YFyUxwq1h4hFCZWNWgApoQzu+gbxueOgOqjzxcV4WTKEmkk9ybV3fKTz3AWng gOzawz528pZ/2Uadk6dDPI/xOkJc1MbUuEqFMZTTBNFS0B7SMxbeHkpXyBhMI9th8on66 TdC5CyZHXB4Ornz80kD/8plHiat2NItSUAPYQs2OvoeGLMcrYEDbDCcP35zQE0d9rtg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793852447; h=DMARC-Filter:Received:DKIM-Filter:DKIM-Signature:Received:Received: Received:Received:From:To:Cc:Subject:Date:Message-Id:X-Mailer: MIME-Version:Content-Transfer-Encoding:X-CMS-MailID:X-Msg-Generator: Content-Type:X-Sendblock-Type:CMS-TYPE:X-CPGSPASS:cpgsPolicy: X-CFilter-Loop:X-CMS-RootMailID:References; bh=slxoBHRYhaDWuQFRl3gCo2MDW72ELcaKt7lNPJR6Efk=; b=4Nx3x7y1WUSJWhZ49NvwfAZzAxn2YGgeBOWsaiaF7UiYKdp0fVo2H+za5ODfxTmIHRes CBAtXHGBxJ443TSaB8AafPyH69lxQUp1xNGS463qH+bxc5KydcFmH8x0DKiNwtSSz/4D/ X/GYCf6kpEno1lPP0b1FocWPa80zhZ1c+hgFM2M0CSVLvBRDUn8Yjf22bcX8DmsHtuImx 3DMe0FpLTWcYu1f3uf8mAmtdfxqQKMH8+tbljBrGrNO3X/+0LxKws2qrffR8X1yCaZouW KJSC9yMq7pxPCoYZSy9wI8Q6wZO7EcCjydIlM78bOY+Z9Pe8TORTBCuhh3QkNZ4YaIg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass header.d=samsung.com header.i=@samsung.com header.a=rsa-sha256 header.s=mail20170921 header.b=iwfUSbk7; arc=none smtp.remote-ip=203.254.224.33 Received: from mailout3.samsung.com (mailout3.samsung.com [203.254.224.33]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 385FD606A33F for ; Thu, 5 Nov 2026 04:20:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 385FD606A33F Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=samsung.com header.i=@samsung.com header.a=rsa-sha256 header.s=mail20170921 header.b=iwfUSbk7 Received: from epcas2p2.samsung.com (unknown [182.195.41.54]) by mailout3.samsung.com (KnoxPortal) with ESMTP id 20261105042042epoutp0384e612ddae329dd20bda0947b13b6125~lC0qz4jHo2143021430epoutp03S for ; Thu, 5 Nov 2026 04:20:42 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout3.samsung.com 20261105042042epoutp0384e612ddae329dd20bda0947b13b6125~lC0qz4jHo2143021430epoutp03S DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1793852442; bh=slxoBHRYhaDWuQFRl3gCo2MDW72ELcaKt7lNPJR6Efk=; h=From:To:Cc:Subject:Date:References:From; b=iwfUSbk7ovbZ0HKDMP4Er6tFDzWFJqfPB16HqN3b2vkJtd2PjW70k/QoKbVR9Xcxa EbneQk1O5gs/dFAc8aUUJjsh89pAyllpBae4MBagBPk+FmhArH8j9I4/R05jPoED11 4fDsYwpzydsIBBCAKi9afR/KkIU5S3H/beGUSFUw= Received: from epsnrtp03.localdomain (unknown [182.195.42.155]) by epcas2p1.samsung.com (KnoxPortal) with ESMTPS id 20261105042041epcas2p1d8577504c1d3e979743d325a4548ef3d~lC0qOsSII1238412384epcas2p1g; Thu, 5 Nov 2026 04:20:41 +0000 (GMT) Received: from epcas2p3.samsung.com (unknown [182.195.38.203]) by epsnrtp03.localdomain (Postfix) with ESMTP id 4jKpyK0hN7z3hhTF; Thu, 5 Nov 2026 04:20:41 +0000 (GMT) Received: from epsmtip1.samsung.com (unknown [182.195.34.30]) by epcas2p2.samsung.com (KnoxPortal) with ESMTPA id 20261105042040epcas2p2af9610d36007ff1e247c8131aeb3edfc~lC0paTTrx2717227172epcas2p2P; Thu, 5 Nov 2026 04:20:40 +0000 (GMT) Received: from ubuntu.dsn.sec.samsung.com (unknown [12.81.221.204]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20261105042040epsmtip1b7167f3bf268af48629fa3526988dc40~lC0pTSD5B2504825048epsmtip1b; Thu, 5 Nov 2026 04:20:40 +0000 (GMT) From: HOYOUNG SEO To: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, bvanassche@acm.org, mkp@kernel.org, martin.petersen@oracle.com, stanleyjhu@google.com, alim.akhtar@samsung.com, kwangwon.min@samsung.com, kwmad.kim@samsung.com, cpgs@samsung.com, h10.kim@samsung.com Cc: HOYOUNG SEO Subject: [PATCH v4 0/2] scsi: ufs: core: Avoid redundant link recovery from the error handler during PM Date: Thu, 5 Nov 2026 13:16:15 +0900 Message-Id: X-Mailer: git-send-email 2.34.1 X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CMS-MailID: 20261105042040epcas2p2af9610d36007ff1e247c8131aeb3edfc X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P X-CPGSPASS: Y cpgsPolicy: CPGSC10-234,Y X-CFilter-Loop: Reflected X-CMS-RootMailID: 20261105042040epcas2p2af9610d36007ff1e247c8131aeb3edfc References: If a LINERESET is reported and the hibern8 exit fails during system resume, both ufshcd_err_handler() and __ufshcd_wl_resume() call ufshcd_link_recovery(), and the two recoveries are not serialized. Patch 1 makes ufshcd_link_recovery() clear the saved errors like ufshcd_reset_and_restore() does, so the error handler does not act on errors that have already been recovered. Patch 2 restricts the early link recovery in ufshcd_err_handler(), which does not hold host_sem, to runtime PM. For system PM the error handler now waits for host_sem, and for shutdown it stops. The early link recovery is kept for runtime suspend and runtime resume. During runtime resume it can still run concurrently with __ufshcd_wl_resume(). Removing it there needs a closer look at the deadlock that it avoids. Changes in v4 (as suggested by Bart Van Assche): - Replace the is_sys_suspended check of v3 patch 2 with a check for runtime PM, which also covers system suspend failure and shutdown. - Add Fixes: tags. - Do not serialize ufshcd_link_recovery() with a mutex: it calls ufshcd_probe_hba(), and a device command timing out inside it ends up in ufshcd_eh_timed_out(), which calls ufshcd_link_recovery() again. Changes in v3: - Patch 2: reword the commit message only, no code change. The error handler does not always run a full recovery after a failed system resume; it stops according to ufshcd_err_handling_should_stop() (e.g. in UFSHCD_STATE_ERROR). Describe this behavior and refer to the commit that added the early link recovery (Sashiko review). - Patch 1: no change. Changes in v2: - Add patch 1. As pointed out by the Sashiko review, saved_err and saved_uic_err are still set after the resume path recovered the link, so with v1 alone ufshcd_err_handler() would run a redundant recovery once host_sem is released. - Patch 2: describe the race and the system/runtime PM difference in the commit message, and add a comment. v3: https://lore.kernel.org/linux-scsi/cover.1792989286.git.hy50.seo@samsung.com/ v2: https://lore.kernel.org/linux-scsi/cover.1792755091.git.hy50.seo@samsung.com/ HOYOUNG SEO (2): scsi: ufs: core: Clear saved errors in ufshcd_link_recovery scsi: ufs: core: Limit early link recovery in the error handler to runtime PM drivers/ufs/core/ufshcd.c | 29 +++++++++++++++++++++++++---- include/ufs/ufshcd.h | 2 ++ 2 files changed, 27 insertions(+), 4 deletions(-) -- 2.34.1