From patchwork Thu Apr 7 07:57:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ulf Hansson X-Patchwork-Id: 8769361 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id ED4DEC0553 for ; Thu, 7 Apr 2016 07:58:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EAD27201D3 for ; Thu, 7 Apr 2016 07:58:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5C7B20115 for ; Thu, 7 Apr 2016 07:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751509AbcDGH56 (ORCPT ); Thu, 7 Apr 2016 03:57:58 -0400 Received: from mail-lb0-f182.google.com ([209.85.217.182]:36659 "EHLO mail-lb0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750784AbcDGH55 (ORCPT ); Thu, 7 Apr 2016 03:57:57 -0400 Received: by mail-lb0-f182.google.com with SMTP id bk9so17514594lbc.3 for ; Thu, 07 Apr 2016 00:57:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=jgxRyXVAlRdkEig4Lu6b/mz3oBxYz7Zt26SgXC11dUI=; b=aL6ccpahURKv5Ch+BZyysPzPKNv6mXdmbxOrI2C4ZBO0gxLIfK7cJmqxsivEmXz/1H XrO88npXQ8bBz/nZIjqR0w+R3rnD3vQu3V/97jiH0qHYeHUlZRtFPYUzKD1yCOWGVXa2 L0rtlLDbPlLFCj04HskTEbQS6QQvn7kdJVai0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=jgxRyXVAlRdkEig4Lu6b/mz3oBxYz7Zt26SgXC11dUI=; b=RvfPIjUA+6g/1lAppU+Bx9AlyULi/r3zYh5LiKVUHAIh7YZ4vUZd6dxj5cnMAjv9BT 6JMHQh0LEhKDoS0BCgwEOVpwunD/TfTqw9CEm3ssGYnrkEiw93HQIXYWynR6u6xHMGsS LRmsSGXpVrdeMHrgBoaCquwpreFvL8OBXvEVNr8ArM6ldQ7JtVqNarLnZF14yP5OhGfP /pp7FjfrRuYz5Oabd0mgOhcZ6zzQR2e4mcdARwwObSoV/bG8oHT+YcGYHkAoWDzR3Aqd D7Dtakvi/b0ZPTiAnizSpHEOR9fhG88cj1+OcfxKLGdjGofDgPKdM1dWan+ICNniRYU3 YZ0A== X-Gm-Message-State: AD7BkJLeOyUesMPr5umFg7Gfvs7mecNjMmt7zulMxBOIbvpca7RlO3lTdiQytfTz5826C1c7 X-Received: by 10.112.72.199 with SMTP id f7mr755165lbv.17.1460015875420; Thu, 07 Apr 2016 00:57:55 -0700 (PDT) Received: from uffe-Latitude-E6430s.ideon.se ([85.235.10.227]) by smtp.gmail.com with ESMTPSA id um4sm1034946lbb.1.2016.04.07.00.57.52 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 07 Apr 2016 00:57:53 -0700 (PDT) From: Ulf Hansson To: linux-mmc@vger.kernel.org, Ulf Hansson Cc: Jaehoon Chung , Adrian Hunter , Jisheng Zhang , Peter Hurley , Laszlo Fiat , linux-kernel@vger.kernel.org, Linus Torvalds , Subject: [PATCH] mmc: block: Use the mmc host device index as the mmcblk device index Date: Thu, 7 Apr 2016 09:57:41 +0200 Message-Id: <1460015861-14004-1-git-send-email-ulf.hansson@linaro.org> X-Mailer: git-send-email 1.9.1 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-7.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 520bd7a8b415 ("mmc: core: Optimize boot time by detecting cards simultaneously") causes regressions for some platforms. These platforms relies on fixed mmcblk device indexes, instead of deploying the defacto standard with UUID/PARTUUID. In other words their rootfs needs to be available at hardcoded paths, like /dev/mmcblk0p2. Such guarantees have never been made by the kernel, but clearly the above commit changes the behaviour. More precisely, because of that the order changes of how cards becomes detected, so do their corresponding mmcblk device indexes. As the above commit significantly improves boot time for some platforms (magnitude of seconds), let's avoid reverting this change but instead restore the behaviour of how mmcblk device indexes becomes picked. By using the same index for the mmcblk device as for the corresponding mmc host device, the probe order of mmc host devices decides the index we get for the mmcblk device. For those platforms that suffers from a regression, one could expect that this updated behaviour should be sufficient to meet their expectations of "fixed" mmcblk device indexes. Another side effect from this change, is that the same index is used for the mmc host device, the mmcblk device and the mmc block queue. That should clarify their relationship. Reported-by: Peter Hurley Reported-by: Laszlo Fiat Cc: Linus Torvalds Fixes: 520bd7a8b415 ("mmc: core: Optimize boot time by detecting cards simultaneously") Cc: Signed-off-by: Ulf Hansson --- drivers/mmc/card/block.c | 18 +----------------- 1 file changed, 1 insertion(+), 17 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 3bdbe50..8a0147d 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -86,7 +86,6 @@ static int max_devices; /* TODO: Replace these with struct ida */ static DECLARE_BITMAP(dev_use, MAX_DEVICES); -static DECLARE_BITMAP(name_use, MAX_DEVICES); /* * There is one mmc_blk_data per slot. @@ -105,7 +104,6 @@ struct mmc_blk_data { unsigned int usage; unsigned int read_only; unsigned int part_type; - unsigned int name_idx; unsigned int reset_done; #define MMC_BLK_READ BIT(0) #define MMC_BLK_WRITE BIT(1) @@ -2202,19 +2200,6 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, goto out; } - /* - * !subname implies we are creating main mmc_blk_data that will be - * associated with mmc_card with dev_set_drvdata. Due to device - * partitions, devidx will not coincide with a per-physical card - * index anymore so we keep track of a name index. - */ - if (!subname) { - md->name_idx = find_first_zero_bit(name_use, max_devices); - __set_bit(md->name_idx, name_use); - } else - md->name_idx = ((struct mmc_blk_data *) - dev_to_disk(parent)->private_data)->name_idx; - md->area_type = area_type; /* @@ -2264,7 +2249,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, */ snprintf(md->disk->disk_name, sizeof(md->disk->disk_name), - "mmcblk%u%s", md->name_idx, subname ? subname : ""); + "mmcblk%u%s", card->host->index, subname ? subname : ""); if (mmc_card_mmc(card)) blk_queue_logical_block_size(md->queue.queue, @@ -2418,7 +2403,6 @@ static void mmc_blk_remove_parts(struct mmc_card *card, struct list_head *pos, *q; struct mmc_blk_data *part_md; - __clear_bit(md->name_idx, name_use); list_for_each_safe(pos, q, &md->part) { part_md = list_entry(pos, struct mmc_blk_data, part); list_del(pos);