From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3x5SNm4J25zDq88 for ; Mon, 10 Jul 2017 11:31:36 +1000 (AEST) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6A1SZXD120576 for ; Sun, 9 Jul 2017 21:31:34 -0400 Received: from e23smtp02.au.ibm.com (e23smtp02.au.ibm.com [202.81.31.144]) by mx0b-001b2d01.pphosted.com with ESMTP id 2bjujyh3xa-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 09 Jul 2017 21:31:34 -0400 Received: from localhost by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 10 Jul 2017 11:31:31 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6A1VSMe5046384 for ; Mon, 10 Jul 2017 11:31:28 +1000 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v6A1VQB1006346 for ; Mon, 10 Jul 2017 11:31:27 +1000 From: Cyril Bur To: linuxppc-dev@lists.ozlabs.org, linux-mtd@lists.infradead.org Cc: benh@kernel.crashing.org, stewart@linux.vnet.ibm.com, dwmw2@infradead.org, rlippert@google.com, alistair@popple.id.au Subject: [PATCH v2 10/10] mtd: powernv_flash: Use opal_async_wait_response_interruptible() Date: Mon, 10 Jul 2017 11:31:06 +1000 In-Reply-To: <20170710013106.27276-1-cyrilbur@gmail.com> References: <20170710013106.27276-1-cyrilbur@gmail.com> Message-Id: <20170710013106.27276-11-cyrilbur@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The OPAL calls performed in this driver shouldn't be using opal_async_wait_response() as this performs a wait_event() which, on long running OPAL calls could result in hung task warnings. wait_event() prevents timely signal delivery which is also undesirable. This patch also attempts to quieten down the use of dev_err() when errors haven't actually occurred and also to return better information up the stack rather than always -EIO. Signed-off-by: Cyril Bur --- drivers/mtd/devices/powernv_flash.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c index d7243b72ba6e..cfa274ba7e40 100644 --- a/drivers/mtd/devices/powernv_flash.c +++ b/drivers/mtd/devices/powernv_flash.c @@ -90,16 +90,34 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, goto out_success; if (rc != OPAL_ASYNC_COMPLETION) { - dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n", + if (rc != OPAL_BUSY) + dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n", op, rc); - rc = -EIO; + rc = opal_error_code(rc); goto out; } - rc = opal_async_wait_response(token, &msg); + rc = opal_async_wait_response_interruptible(token, &msg); if (rc) { - dev_err(dev, "opal async wait failed (rc %d)\n", rc); - rc = -EIO; + /* + * Awkward, we've been interrupted but we cannot return. If we + * do return the mtd core will free the buffer we've just + * passed to OPAL but OPAL will continue to read or write from + * that memory. + * Future work will introduce a call to tell OPAL to stop + * using the buffer. + * It may be tempting to ultimately return 0 if we're doing a + * read or a write since we are going to end up waiting until + * OPAL is done. However, because the MTD core sends us the + * userspace request in chunks, we must report EINTR so that + * it doesn't just send us the next chunk, thus defeating the + * point of the _interruptible wait. + */ + rc = -EINTR; + if (op == FLASH_OP_READ || op == FLASH_OP_WRITE) { + if (opal_async_wait_response(token, &msg)) + dev_err(dev, "opal async wait failed (rc %d)\n", rc); + } goto out; } -- 2.13.2