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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 9E132C43610 for ; Mon, 12 Nov 2018 00:20:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 681512084C for ; Mon, 12 Nov 2018 00:20:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="U4qKkenf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 681512084C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730282AbeKLKLD (ORCPT ); Mon, 12 Nov 2018 05:11:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:58352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729637AbeKLIQv (ORCPT ); Mon, 12 Nov 2018 03:16:51 -0500 Received: from localhost (unknown [206.108.79.134]) (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 80C4B214E0; Sun, 11 Nov 2018 22:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975215; bh=VrzXONenTv2kPRObLVJSw/76mri7jG8Rt5AkAC2Cby8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U4qKkenfg+xM1Elbxx+oOPgz4NB7k6SxU7aBEU20dyIEuXZa7FMS49At8u+70UBdz 7RjIDncKgeCk/kyo9MhNWMvqNb6/kbzCG63O/l1ed3gxlItqK2IxjcIdZRmIuXLieO 9reA3l2NcLN620TYajzGNUPdu1aTIT7USu4m9e9Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= , Mark Brown Subject: [PATCH 4.19 010/361] spi: bcm-qspi: switch back to reading flash using smaller chunks Date: Sun, 11 Nov 2018 14:15:57 -0800 Message-Id: <20181111221621.418979932@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221619.915519183@linuxfoundation.org> References: <20181111221619.915519183@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rafał Miłecki commit 940ec770c295682993d1cccce3081fd7c74fece8 upstream. Fixing/optimizing bcm_qspi_bspi_read() performance introduced two changes: 1) It added a loop to read all requested data using multiple BSPI ops. 2) It bumped max size of a single BSPI block request from 256 to 512 B. The later change resulted in occasional BSPI timeouts causing a regression. For some unknown reason hardware doesn't always handle reads as expected when using 512 B chunks. In such cases it may happen that BSPI returns amount of requested bytes without the last 1-3 ones. It provides the remaining bytes later but doesn't raise an interrupt until another LR start. Switching back to 256 B reads fixes that problem and regression. Fixes: 345309fa7c0c ("spi: bcm-qspi: Fix bcm_qspi_bspi_read() performance") Signed-off-by: Rafał Miłecki Signed-off-by: Mark Brown Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-bcm-qspi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/spi/spi-bcm-qspi.c +++ b/drivers/spi/spi-bcm-qspi.c @@ -89,7 +89,7 @@ #define BSPI_BPP_MODE_SELECT_MASK BIT(8) #define BSPI_BPP_ADDR_SELECT_MASK BIT(16) -#define BSPI_READ_LENGTH 512 +#define BSPI_READ_LENGTH 256 /* MSPI register offsets */ #define MSPI_SPCR0_LSB 0x000