From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XZCtcjZw" Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EADA9D5; Mon, 11 Dec 2023 00:03:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702281840; x=1733817840; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=K+OG1koP1ULrySQIRiy7xz7OlRKwcfL/LiW/qwKPQP0=; b=XZCtcjZwLBm2S+hLv2ptqK9bf400ZPH5VVfw76955EFbU2TTDRoYZzNL cLnWYkgRxWlXNHrXNt8s3AUuOKYZcaWa0/xIBTspSEGYluVVJdssqfIql 97CJcYJXgAuFRx1JV39soMCjnHk4JbCMyJSw5dER+gkv1ZvonS35By0aJ b2yMt94nhGcsuSZ1Lk+OeVt9DzH4P0qFzN1EpDCgzJNHuqi3Z8zW3LbPS p/5q6BxesDQMyn+KZybiInxJ4B8hRlyC/oLjPRHU3OBqMWYRQdwXqjCEH faNIp6CU88sq5V1z7iRNMR85S2ntiC3b4/Y8zJzWprtokmvZvE+7hjAJG w==; X-IronPort-AV: E=McAfee;i="6600,9927,10920"; a="1448392" X-IronPort-AV: E=Sophos;i="6.04,267,1695711600"; d="scan'208";a="1448392" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Dec 2023 00:03:59 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10920"; a="1104376725" X-IronPort-AV: E=Sophos;i="6.04,267,1695711600"; d="scan'208";a="1104376725" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO [10.0.2.15]) ([10.252.46.23]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Dec 2023 00:03:54 -0800 Message-ID: Date: Mon, 11 Dec 2023 10:03:51 +0200 Precedence: bulk X-Mailing-List: linux-mmc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mmc: rpmb: do not force a retune before RPMB switch To: Avri Altman , Jorge Ramirez-Ortiz , "ulf.hansson@linaro.org" , "christian.loehle@arm.com" Cc: "jinpu.wang@ionos.com" , "axboe@kernel.dk" , "beanhuo@micron.com" , "yibin.ding@unisoc.com" , "victor.shih@genesyslogic.com.tw" , "asuk4.q@gmail.com" , "hkallweit1@gmail.com" , "yangyingliang@huawei.com" , "yebin10@huawei.com" , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20231204150111.3320071-1-jorge@foundries.io> Content-Language: en-US From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 6/12/23 09:02, Avri Altman wrote: >> >> On 4/12/23 17:01, Jorge Ramirez-Ortiz wrote: >>> Requesting a retune before switching to the RPMB partition has been >>> observed to cause CRC errors on the RPMB reads (-EILSEQ). >> >> There are still 2 concerns: >> 1) We don't really know the root cause. Have you determined if here are >> CRC errors in the main partition also? >> 2) Forcing this on everyone >> >> The original idea was that because re-tuning cannot be done in RPMB, the >> need to re-rune in RPMB could be avoided by always re-tuning before >> switching to RPMB and then switching straight back. IIRC re-tuning should >> guarantee at least 4MB more I/O without issue. > Performance is hardly an issue in the context of RPMB access - > For most cases it’s a single frame. Not sure why you bring up performance. SDHCI spec says: "To enable inserting the re-tuning procedure during data transfers, the data length per read/write command shall be limited up to 4MB." Which implies re-tuning is needed at most every 4MB, so re-tuning before RPMB switch and switching straight back, means re-tuning should never be needed in RPMB. > > Thanks, > Avri > >> >> The alternative to dropping re-tuning in this case could be to add a retry loop >> for MMC_DRV_OP_IOCTL_RPMB if the error is -EILSEQ >> >> >>> >>> Since RPMB reads can not be retried, the clients would be directly >>> affected by the errors. >>> >>> This commit disables the request prior to RPMB switching while >>> allowing the pause interface to still request a retune before the >>> pause for other use cases. >>> >>> This was verified with the sdhci-of-arasan driver (ZynqMP) configured >>> for HS200 using two separate eMMC cards (DG4064 and 064GB2). In both >>> cases, the error was easy to reproduce triggering every few tenths of >>> reads. >>> >>> Signed-off-by: Jorge Ramirez-Ortiz >>> --- >>> drivers/mmc/core/block.c | 2 +- >>> drivers/mmc/core/host.c | 7 ++++--- >>> drivers/mmc/core/host.h | 2 +- >>> 3 files changed, 6 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index >>> f9a5cffa64b1..1d69078ad9b2 100644 >>> --- a/drivers/mmc/core/block.c >>> +++ b/drivers/mmc/core/block.c >>> @@ -859,7 +859,7 @@ static int mmc_blk_part_switch_pre(struct >> mmc_card *card, >>> if (ret) >>> return ret; >>> } >>> - mmc_retune_pause(card->host); >>> + mmc_retune_pause(card->host, false); >>> } >>> >>> return ret; >>> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index >>> 096093f7be00..a9b95aaa2235 100644 >>> --- a/drivers/mmc/core/host.c >>> +++ b/drivers/mmc/core/host.c >>> @@ -119,13 +119,14 @@ void mmc_retune_enable(struct mmc_host >> *host) >>> >>> /* >>> * Pause re-tuning for a small set of operations. The pause begins >>> after the >>> - * next command and after first doing re-tuning. >>> + * next command and, if retune is set, after first doing re-tuning. >>> */ >>> -void mmc_retune_pause(struct mmc_host *host) >>> +void mmc_retune_pause(struct mmc_host *host, bool retune) >>> { >>> if (!host->retune_paused) { >>> host->retune_paused = 1; >>> - mmc_retune_needed(host); >>> + if (retune) >>> + mmc_retune_needed(host); >> >> Better to just drop mmc_retune_needed(host); >> >>> mmc_retune_hold(host); >> >> There is still a small chance that re-tuning is needed anyway in which case it >> will still be done. >> >>> } >>> } >>> diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h index >>> 48c4952512a5..321776b52270 100644 >>> --- a/drivers/mmc/core/host.h >>> +++ b/drivers/mmc/core/host.h >>> @@ -18,7 +18,7 @@ void mmc_retune_disable(struct mmc_host *host); >>> void mmc_retune_hold(struct mmc_host *host); void >>> mmc_retune_release(struct mmc_host *host); int mmc_retune(struct >>> mmc_host *host); -void mmc_retune_pause(struct mmc_host *host); >>> +void mmc_retune_pause(struct mmc_host *host, bool retune); >>> void mmc_retune_unpause(struct mmc_host *host); >>> >>> static inline void mmc_retune_clear(struct mmc_host *host) >