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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E85E0C38142 for ; Wed, 18 Jan 2023 02:43:51 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pHyPH-0005WA-Op; Tue, 17 Jan 2023 21:42:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pHyPG-0005VE-2u; Tue, 17 Jan 2023 21:42:30 -0500 Received: from out2-smtp.messagingengine.com ([66.111.4.26]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pHyPE-0006s4-El; Tue, 17 Jan 2023 21:42:29 -0500 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id DDDA15C0116; Tue, 17 Jan 2023 21:42:26 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Tue, 17 Jan 2023 21:42:26 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pjd.dev; h=cc:cc :content-transfer-encoding:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm1; t=1674009746; x=1674096146; bh=Z8 b4TuMq0IyBoljG29VQAgDtZYdTTN29FtaPFHe089Y=; b=wW0fx4xzpT+fBpuZMG 2qGL1pYpP1Cu/wGeTrTx0boyYCRnupYxiRlh6UfIRR1M7j2uK1du0s+W5Lgu/2Ps mA4SQvfBtmHCL6IAvSlq6vSOJT1E4hYLt3gTLz61Gwb5+ylSQMwg6rrhWdPkyhEi ZeszjYdF1pMjy6EX9hikk9nHGBonG0IEZbOgqKvcU8lK5E368C4Nap6Whp/CI6cW /pyO7PmDx/EIJPBtln0eqAXZTmqYqvBcMLwHUAaH7QjE64YW4Y205F8CKXHS56Er z48itJjyVKFhAAkZ21Wq1HPYZNXV43rizudQthT3z+uWBhSEjxOkFlEBjyIhfLfc 4nsw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm3; t=1674009746; x=1674096146; bh=Z8b4TuMq0IyBo ljG29VQAgDtZYdTTN29FtaPFHe089Y=; b=GMoxywx5vqd4M2joGmW6H0t+nf94V NSkJ71uZx160Q8zv7i/s1XY50wwvVS3fJTrVp6PrZTnmTT88f+0Z8CsI/b11WHRn f+kxOSSrU+TfumYnnymDY3JgCeURtTvg2JHsv86w1uIyhgUJyD1qOw3/bX+GNM5Q X/YNAb2ppKn57LhCuymXqVYu2IsOVJiX2IelPfcmF09vNpEZ7rGtbXkMVy+BvEHB EQqmDb9FclJNLcLnWRUB2Xpef0BUblyfkDiQiRZ42FioSzj6SBrf5VMPRcDA5uau MrOaa0UQ3skLfQtYuNThjrrx69BUSWIkMwgMj+BLmxpLPtEwtH4CDvTxw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedruddtjedgheduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenuchmihhsshhinhhgucfvqfcufhhivghlugculdeftd dmnegoteeftdduqddtudculdduhedmnecujfgurhephffvvefufffkofgjfhgggfestdek redtredttdenucfhrhhomheprfgvthgvrhcuffgvlhgvvhhorhihrghsuceophgvthgvrh esphhjugdruggvvheqnecuggftrfgrthhtvghrnhepteelgfeuleeffffffeekiefghfej uefgtdfgteeigeekvdefffevieekvdelteevnecuvehluhhsthgvrhfuihiivgeptdenuc frrghrrghmpehmrghilhhfrhhomhepphgvthgvrhesphhjugdruggvvh X-ME-Proxy: Feedback-ID: i9e814621:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 17 Jan 2023 21:42:25 -0500 (EST) From: Peter Delevoryas To: Cc: peter@pjd.dev, clg@kaod.org, peter.maydell@linaro.org, andrew@aj.id.au, joel@jms.id.au, hskinnemoen@google.com, kfting@nuvoton.com, qemu-arm@nongnu.org, qemu-devel@nongnu.org, philmd@linaro.org Subject: [PATCH v4 5/5] hw/nvram/eeprom_at24c: Make reset behavior more like hardware Date: Tue, 17 Jan 2023 18:42:14 -0800 Message-Id: <20230118024214.14413-6-peter@pjd.dev> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230118024214.14413-1-peter@pjd.dev> References: <20230118024214.14413-1-peter@pjd.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=66.111.4.26; envelope-from=peter@pjd.dev; helo=out2-smtp.messagingengine.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org EEPROM's are a form of non-volatile memory. After power-cycling an EEPROM, I would expect the I2C state machine to be reset to default values, but I wouldn't really expect the memory to change at all. The current implementation of the at24c EEPROM resets its internal memory on reset. This matches the specification in docs/devel/reset.rst: Cold reset is supported by every resettable object. In QEMU, it means we reset to the initial state corresponding to the start of QEMU; this might differ from what is a real hardware cold reset. It differs from other resets (like warm or bus resets) which may keep certain parts untouched. But differs from my intuition. For example, if someone writes some information to an EEPROM, then AC power cycles their board, they would expect the EEPROM to retain that information. It's very useful to be able to test things like this in QEMU as well, to verify software instrumentation like determining the cause of a reboot. Fixes: 5d8424dbd3e8 ("nvram: add AT24Cx i2c eeprom") Signed-off-by: Peter Delevoryas Reviewed-by: Joel Stanley --- hw/nvram/eeprom_at24c.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c index f8d751fa278d..5074776bff04 100644 --- a/hw/nvram/eeprom_at24c.c +++ b/hw/nvram/eeprom_at24c.c @@ -185,18 +185,6 @@ static void at24c_eeprom_realize(DeviceState *dev, Error **errp) } ee->mem = g_malloc0(ee->rsize); - -} - -static -void at24c_eeprom_reset(DeviceState *state) -{ - EEPROMState *ee = AT24C_EE(state); - - ee->changed = false; - ee->cur = 0; - ee->haveaddr = 0; - memset(ee->mem, 0, ee->rsize); if (ee->init_rom) { @@ -214,6 +202,16 @@ void at24c_eeprom_reset(DeviceState *state) } } +static +void at24c_eeprom_reset(DeviceState *state) +{ + EEPROMState *ee = AT24C_EE(state); + + ee->changed = false; + ee->cur = 0; + ee->haveaddr = 0; +} + static Property at24c_eeprom_props[] = { DEFINE_PROP_UINT32("rom-size", EEPROMState, rsize, 0), DEFINE_PROP_BOOL("writable", EEPROMState, writable, true), -- 2.39.0