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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F38DBC43334 for ; Mon, 27 Jun 2022 10:08:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233543AbiF0KIp (ORCPT ); Mon, 27 Jun 2022 06:08:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233176AbiF0KIo (ORCPT ); Mon, 27 Jun 2022 06:08:44 -0400 Received: from smtp2.axis.com (smtp2.axis.com [195.60.68.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE6FA63B9; Mon, 27 Jun 2022 03:08:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1656324523; x=1687860523; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=IfH4/auxP0BAKuTQeGybZpgGABQyp48s3Z6um0lD/Hs=; b=fWZ21eVjCbKnjljkJYQjleMbQf4e8TtlglcW8XlUr+q601bze3yiwO17 QwqZvYWhAyXbflR3EbzSqJWEDiq8+hBOzdikgi1nqIsnVUx81IJtsiZTr Ko3tqTqY7KauVnfPAvzfy4W+xaDUCQGMr8B2t2LSXM+s/gzjGgK6Zj2y8 DVnR6vmquVzzRakwdRTh4znVXVx/XtwoGznUWPhwZhqyARHjyLZ+Ymvtp yBKpEkh6v0HxMGyPCiUw3GQMHEfrKbGF7P+23Qd7UEWUG7wbXpK7hbG/6 lKB6TpOxNok7i3rev+zpYojVX5dD1fJoHiEoyoCBP9HgI5EoyFDvSY+jH Q==; Date: Mon, 27 Jun 2022 12:08:40 +0200 From: Vincent Whitchurch To: Ulf Hansson CC: kernel , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] mmc: core: Allow speed modes to be adjusted via module param Message-ID: <20220627100840.GA12705@axis.com> References: <20220623080009.1775574-1-vincent.whitchurch@axis.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On Thu, Jun 23, 2022 at 03:53:41PM +0200, Ulf Hansson wrote: > On Thu, 23 Jun 2022 at 10:00, Vincent Whitchurch > wrote: > > During board verification, there is a need to test the various supported > > eMMC/SD speed modes. However, since the framework chooses the best mode > > supported by the card and the host controller's caps, this currently > > necessitates changing the devicetree for every iteration. > > > > To make changing the modes easier, allow the various host controller > > capabilities to be cleared via a module parameter. (A per-controller > > debugfs wouldn't work since the controller needs to be re-probed to > > trigger re-init of cards. A module parameter is used instead of a > > I think we could make use of a per-controller debugfs thing, if used > in combination with MMC_CAP_AGGRESSIVE_PM and runtime PM. > > As runtime PM also has sysfs interface for each device, we can control > runtime PM for the card's device (to trigger re-initialization of the > card). In between runtime suspend/resume of the card's device, we > should be able to change the supported speed modes, through debug fs. > > Would this work for you? I got it to work with the below commands and the following patch. Note that: (1) MMC_CAP_AGGRESSIVE_PM also needs to be turned on via debugfs to avoid having to patch the kernel. The cap is checked on every call to runtime_suspend so it (currently) works to set it without re-probing the host. (2) I had to call mmc_select_card_type() even if there is an old card since currently it's only called from mmc_decode_ext_csd(). Also, unlike the module parameter, this can't be set from bootargs, but that part is not important for my use case. root@(none):/sys/kernel/debug/mmc0# grep timing ios timing spec: 9 (mmc HS200) // Turn on MMC_CAP_AGGRESSIVE_PM and re-trigger runtime suspend root@(none):/sys/kernel/debug/mmc0# echo $(($(cat caps) | (1 << 7))) > caps root@(none):/sys/kernel/debug/mmc0# echo on > /sys/bus/mmc/devices/mmc0\:0001/power/control root@(none):/sys/kernel/debug/mmc0# echo auto > /sys/bus/mmc/devices/mmc0\:0001/power/control // MMC_CAP2_HS200_1_8V_SDR root@(none):/sys/kernel/debug/mmc0# echo $(($(cat caps2) & ~(1 << 5))) > caps2 root@(none):/sys/kernel/debug/mmc0# echo on > /sys/bus/mmc/devices/mmc0\:0001/power/control root@(none):/sys/kernel/debug/mmc0# grep timing ios timing spec: 8 (mmc DDR52) 8<---- diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c index 3fdbc801e64a..721925300611 100644 --- a/drivers/mmc/core/debugfs.c +++ b/drivers/mmc/core/debugfs.c @@ -12,9 +12,12 @@ #include #include #include +#include #include #include +#include +#include #include "core.h" #include "card.h" @@ -223,6 +226,47 @@ static int mmc_clock_opt_set(void *data, u64 val) DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set, "%llu\n"); +static int mmc_caps_get(void *data, u64 *val) +{ + *val = *(u32 *)data; + return 0; +} + +static int mmc_caps_set(void *data, u64 val) +{ + u32 *caps = data; + u32 diff = *caps ^ val; + u32 allowed = MMC_CAP_AGGRESSIVE_PM | + MMC_CAP_SD_HIGHSPEED | + MMC_CAP_MMC_HIGHSPEED | + MMC_CAP_UHS | + MMC_CAP_DDR; + + if (diff & ~allowed) + return -EINVAL; + + *caps = val; + + return 0; +} + +static int mmc_caps2_set(void *data, u64 val) +{ + u32 *caps = data; + u32 diff = *caps ^ val; + u32 allowed = MMC_CAP2_HSX00_1_8V | MMC_CAP2_HSX00_1_2V; + + if (diff & ~allowed) + return -EINVAL; + + *caps = val; + + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(mmc_caps_fops, mmc_caps_get, mmc_caps_set, "0x%08llx\n"); +DEFINE_DEBUGFS_ATTRIBUTE(mmc_caps2_fops, mmc_caps_get, mmc_caps2_set, "0x%08llx\n"); + void mmc_add_host_debugfs(struct mmc_host *host) { struct dentry *root; @@ -231,8 +275,10 @@ void mmc_add_host_debugfs(struct mmc_host *host) host->debugfs_root = root; debugfs_create_file("ios", S_IRUSR, root, host, &mmc_ios_fops); - debugfs_create_x32("caps", S_IRUSR, root, &host->caps); - debugfs_create_x32("caps2", S_IRUSR, root, &host->caps2); + debugfs_create_file("caps", S_IRUSR | S_IWUSR, root, &host->caps, + &mmc_caps_fops); + debugfs_create_file("caps2", S_IRUSR | S_IWUSR, root, &host->caps2, + &mmc_caps2_fops); debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host, &mmc_clock_fops); diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 89cd48fcec79..c79c26add3da 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1730,7 +1730,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, /* Erase size depends on CSD and Extended CSD */ mmc_set_erase_size(card); - } + } else + mmc_select_card_type(card); /* Enable ERASE_GRP_DEF. This bit is lost after a reset or power off. */ if (card->ext_csd.rev >= 3) {