From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 392EBC4CED1 for ; Thu, 3 Oct 2019 16:01:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E230222CC for ; Thu, 3 Oct 2019 16:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118515; bh=5u2zAl7BkqOE1FqzDrXTn5nzPaiQIpAI/eo9TlZSobQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GVbYLfNTPJtbkhvOn3sIrAPpg17dEVojfasFG9WV/IyV7rN92xVWYN7f9wq1J2OZQ 6YOgFvf7znqkkrEyOPtJTiaiGOSKMC3f+ff2lJ2RSzI2jte8vz5biTdezgGpk/apAW jKR1CfUVaslw+po3CyYyCCYPK6O/bxyX6IFHHFcM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731926AbfJCQBy (ORCPT ); Thu, 3 Oct 2019 12:01:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:46370 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730314AbfJCQBu (ORCPT ); Thu, 3 Oct 2019 12:01:50 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C36A6207FF; Thu, 3 Oct 2019 16:01:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118509; bh=5u2zAl7BkqOE1FqzDrXTn5nzPaiQIpAI/eo9TlZSobQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kFg9TRgfC7s9jRlK4FhhmHCKqSZ430+FMUV+hUUl+rxZDx9z3yFFfHMaE/1ufC59P dxm91S12jidhUo/TP99sMBTtAdeIM3YjE/hmz/qEqZt7I9C1GJcXKVtZXnH6UVH4jk KS2zD0VRXqEfzOYOtwHiNytekRFukKnGORcC/FG4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Packham , Joakim Tjernlund , linux-mtd@lists.infradead.org, Fabio Bettoni , Felix Fietkau , Hauke Mehrtens , Tokunori Ikegami , Vignesh Raghavendra Subject: [PATCH 4.9 006/129] mtd: cfi_cmdset_0002: Use chip_good() to retry in do_write_oneword() Date: Thu, 3 Oct 2019 17:52:09 +0200 Message-Id: <20191003154322.117166351@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154318.081116689@linuxfoundation.org> References: <20191003154318.081116689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tokunori Ikegami commit 37c673ade35c707d50583b5b25091ff8ebdeafd7 upstream. As reported by the OpenWRT team, write requests sometimes fail on some platforms. Currently to check the state chip_ready() is used correctly as described by the flash memory S29GL256P11TFI01 datasheet. Also chip_good() is used to check if the write is succeeded and it was implemented by the commit fb4a90bfcd6d8 ("[MTD] CFI-0002 - Improve error checking"). But actually the write failure is caused on some platforms and also it can be fixed by using chip_good() to check the state and retry instead. Also it seems that it is caused after repeated about 1,000 times to retry the write one word with the reset command. By using chip_good() to check the state to be done it can be reduced the retry with reset. It is depended on the actual flash chip behavior so the root cause is unknown. Cc: Chris Packham Cc: Joakim Tjernlund Cc: linux-mtd@lists.infradead.org Cc: stable@vger.kernel.org Reported-by: Fabio Bettoni Signed-off-by: Felix Fietkau Signed-off-by: Hauke Mehrtens Signed-off-by: Tokunori Ikegami [vigneshr@ti.com: Fix a checkpatch warning] Signed-off-by: Vignesh Raghavendra Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/chips/cfi_cmdset_0002.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) --- a/drivers/mtd/chips/cfi_cmdset_0002.c +++ b/drivers/mtd/chips/cfi_cmdset_0002.c @@ -1624,29 +1624,35 @@ static int __xipram do_write_oneword(str continue; } - if (time_after(jiffies, timeo) && !chip_ready(map, adr)){ + /* + * We check "time_after" and "!chip_good" before checking + * "chip_good" to avoid the failure due to scheduling. + */ + if (time_after(jiffies, timeo) && !chip_good(map, adr, datum)) { xip_enable(map, chip, adr); printk(KERN_WARNING "MTD %s(): software timeout\n", __func__); xip_disable(map, chip, adr); + ret = -EIO; break; } - if (chip_ready(map, adr)) + if (chip_good(map, adr, datum)) break; /* Latency issues. Drop the lock, wait a while and retry */ UDELAY(map, chip, adr, 1); } + /* Did we succeed? */ - if (!chip_good(map, adr, datum)) { + if (ret) { /* reset on all failures. */ map_write( map, CMD(0xF0), chip->start ); /* FIXME - should have reset delay before continuing */ - if (++retry_cnt <= MAX_RETRIES) + if (++retry_cnt <= MAX_RETRIES) { + ret = 0; goto retry; - - ret = -EIO; + } } xip_enable(map, chip, adr); op_done: