From patchwork Wed Oct 30 22:03:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 839775 Received: from 009.lax.mailroute.net (009.lax.mailroute.net [199.89.1.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 91D1E1991DF for ; Wed, 30 Oct 2024 22:03:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730325819; cv=none; b=GMVlgh008ZstFPp6jq+Fc5ivYq53c0e6fBnARqkM+Tlm8YPMngnonFW1swulpa7k+tgNt1aLS3hv30bipeb2GHlechr+Zf2h++Hv/xhPU6rIlquJcW5auve/TtOVNNFDoO7kJCiMV0PM0OV3zRhPpEvHCOpSyxM6Hx2B6RsQIUU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730325819; c=relaxed/simple; bh=IS7+NnAQDvnqe4jpVdXgZI25hBvGzY5cUHEkcJ1tImo=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Z48jVyDxHQqbwl/kYJ/bY17pNJVkclwpwRjcGXLK32mhK/4yqsnaSx+lorPkme6DFSnYHjb6LLeyQ8rP+H/6ccjOhqmsqoRHv5hqTfklQRE+67wm7qv7/O6ZpeslEByifyzaE+UEPq8EZvR+w5kkbmxMlmme/L/uaaSaBsvsZ1U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=T49Nng5Z; arc=none smtp.client-ip=199.89.1.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="T49Nng5Z" Received: from localhost (localhost [127.0.0.1]) by 009.lax.mailroute.net (Postfix) with ESMTP id 4Xf1NS6wCdzlgMW3; Wed, 30 Oct 2024 22:03:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:mime-version:x-mailer:message-id:date :date:subject:subject:from:from:received:received; s=mr01; t= 1730325813; x=1732917814; bh=HKNpsaRoB0Mq0U1sRMbUzma/WvNOP8AxD/P QMMOAH+0=; b=T49Nng5Zg3b7f4YaELkN01s3bky6CSQ67PeNlXVIs+ShTyXekwj kQwFht9kkBUnAI9IIrX4D3YP3pWqy3WHRlEHUi8xWnrjV0LJDAcdxPxiQq9A8WcK z3cxtgNbyWuvLk9DlPr3P00erek0hvEKEqzY/NbtEDE8MwpxpKgNRoSyypl7z+rT TCuJllYjGSU0gM8e52OP5cRw9k39mqAVNnH+KLMcC543nvASUUgOzTO3AORTpDhu 7F2x5/mADLSjVM2miMlDAd6TlQBJA1ylEAv7Stus6RVZcZ4Mfu1u6+BDuC83BLLm g8Xbja0c6UitCSaaMH8n2XU0RqaMfPb9+XQ== X-Virus-Scanned: by MailRoute Received: from 009.lax.mailroute.net ([127.0.0.1]) by localhost (009.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id TSUVaObl7R5I; Wed, 30 Oct 2024 22:03:33 +0000 (UTC) Received: from bvanassche.mtv.corp.google.com (unknown [104.135.204.82]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 009.lax.mailroute.net (Postfix) with ESMTPSA id 4Xf1NL6YrSzlgMVx; Wed, 30 Oct 2024 22:03:30 +0000 (UTC) From: Bart Van Assche To: "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, Bart Van Assche , Alan Stern , Douglas Gilbert , "James E.J. Bottomley" , James Bottomley Subject: [PATCH] scsi: sg: Enable runtime power management Date: Wed, 30 Oct 2024 15:03:10 -0700 Message-ID: <20241030220310.1373569-1-bvanassche@acm.org> X-Mailer: git-send-email 2.47.0.163.g1226f6d8fa-goog Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In 2010, runtime power management support was implemented in the SCSI core. The description of patch "[SCSI] implement runtime Power Management" mentions that the sg driver is skipped but not why. This patch enables runtime power management even if an instance of the sg driver is held open. Enabling runtime PM for the sg driver is safe because all interactions of the sg driver with the SCSI device pass through the block layer (blk_execute_rq_nowait()) and the block layer already supports runtime PM. Cc: Alan Stern Cc: Douglas Gilbert Fixes: bc4f24014de5 ("[SCSI] implement runtime Power Management") Signed-off-by: Bart Van Assche Acked-by: Alan Stern --- drivers/scsi/sg.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index f86be197fedd..84334ab39c81 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -307,10 +307,6 @@ sg_open(struct inode *inode, struct file *filp) if (retval) goto sg_put; - retval = scsi_autopm_get_device(device); - if (retval) - goto sdp_put; - /* scsi_block_when_processing_errors() may block so bypass * check if O_NONBLOCK. Permits SCSI commands to be issued * during error recovery. Tread carefully. */ @@ -318,7 +314,7 @@ sg_open(struct inode *inode, struct file *filp) scsi_block_when_processing_errors(device))) { retval = -ENXIO; /* we are in error recovery for this device */ - goto error_out; + goto sdp_put; } mutex_lock(&sdp->open_rel_lock); @@ -371,8 +367,6 @@ sg_open(struct inode *inode, struct file *filp) } error_mutex_locked: mutex_unlock(&sdp->open_rel_lock); -error_out: - scsi_autopm_put_device(device); sdp_put: kref_put(&sdp->d_ref, sg_device_destroy); scsi_device_put(device); @@ -392,7 +386,6 @@ sg_release(struct inode *inode, struct file *filp) SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n")); mutex_lock(&sdp->open_rel_lock); - scsi_autopm_put_device(sdp->device); kref_put(&sfp->f_ref, sg_remove_sfp); sdp->open_cnt--;