From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:54914 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750926AbdBTFNm (ORCPT ); Mon, 20 Feb 2017 00:13:42 -0500 Subject: Patch "mmc: core: fix multi-bit bus width without high-speed mode" has been added to the 4.9-stable tree To: anssi.hannula@bitwise.fi, gregkh@linuxfoundation.org, ulf.hansson@linaro.org Cc: , From: Date: Mon, 20 Feb 2017 06:13:18 +0100 Message-ID: <148756759819022@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled mmc: core: fix multi-bit bus width without high-speed mode to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-core-fix-multi-bit-bus-width-without-high-speed-mode.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 3d4ef329757cfd5e0b23cce97cdeca7e2df89c99 Mon Sep 17 00:00:00 2001 From: Anssi Hannula Date: Mon, 13 Feb 2017 13:46:41 +0200 Subject: mmc: core: fix multi-bit bus width without high-speed mode From: Anssi Hannula commit 3d4ef329757cfd5e0b23cce97cdeca7e2df89c99 upstream. Commit 577fb13199b1 ("mmc: rework selection of bus speed mode") refactored bus width selection code to mmc_select_bus_width(). However, it also altered the behavior to not call the selection code in non-high-speed modes anymore. This causes 1-bit mode to always be used when the high-speed mode is not enabled, even though 4-bit and 8-bit bus are valid bus widths in the backwards-compatibility (legacy) mode as well (see e.g. 5.3.2 Bus Speed Modes in JEDEC 84-B50). This results in a significant regression in transfer speeds. Fix the code to allow 4-bit and 8-bit widths even without high-speed mode, as before. Tested with a Zynq-7000 PicoZed 7020 board. Fixes: 577fb13199b1 ("mmc: rework selection of bus speed mode") Signed-off-by: Anssi Hannula Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/core/mmc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1690,10 +1690,10 @@ static int mmc_init_card(struct mmc_host err = mmc_select_hs400(card); if (err) goto free_card; - } else if (mmc_card_hs(card)) { + } else { /* Select the desired bus width optionally */ err = mmc_select_bus_width(card); - if (err > 0) { + if (err > 0 && mmc_card_hs(card)) { err = mmc_select_hs_ddr(card); if (err) goto free_card; Patches currently in stable-queue which might be from anssi.hannula@bitwise.fi are queue-4.9/mmc-core-fix-multi-bit-bus-width-without-high-speed-mode.patch