From patchwork Tue Sep 12 14:31:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Kaiser X-Patchwork-Id: 13381837 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 06BD6CA0EEB for ; Tue, 12 Sep 2023 14:35:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=4V2HalViOeq8Y7neV1fvOBQZpACpiYpj3oyltxKdgHQ=; b=h6H2QVB/sLdD2/ owa8W1+chAPw+BGFrO1bnVOLW6iRtqxEnNWBoXg0qI6IDrLo+v0XUOs1K2ZiRbne2ruZM1eEFLhzr +npuCGQKVBwQ37AydBCWwgv5oDlrWblRUl7bcJ+cJFTMBX9Jh16JpY3ZgSGMsUtOcnHfajBGr8xoH FFa+ZZ8gUVlEE/6Hk0hlYKpdvdt33QyNylUIhDHaz+UCDhRle4WJDVPx00FibXbBV6goa3JvwekxK ZfvkbIC+NsphmVTkedEjBpztNC/aefgdXfwyiH/cS8ViS8whY8oEqtWmG/IJLQDcD9UboPCSVNcst yIHV1c7aVo31QPR4AHBw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qg4Th-003bAp-0i; Tue, 12 Sep 2023 14:34:57 +0000 Received: from viti.kaiser.cx ([2a01:238:43fe:e600:cd0c:bd4a:7a3:8e9f]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qg4Te-003b8X-07 for linux-arm-kernel@lists.infradead.org; Tue, 12 Sep 2023 14:34:55 +0000 Received: from dslb-178-004-201-190.178.004.pools.vodafone-ip.de ([178.4.201.190] helo=martin-debian-2.paytec.ch) by viti.kaiser.cx with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1qg4TU-0005wr-LB; Tue, 12 Sep 2023 16:34:44 +0200 From: Martin Kaiser To: Herbert Xu Cc: linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Martin Kaiser Subject: [PATCH 2/2] hwrng: imx-rngc - reasonable timeout for initial seed Date: Tue, 12 Sep 2023 16:31:18 +0200 Message-Id: <20230912143117.55965-3-martin@kaiser.cx> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230912143117.55965-1-martin@kaiser.cx> References: <20230912143117.55965-1-martin@kaiser.cx> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230912_073454_214251_230854F7 X-CRM114-Status: GOOD ( 11.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Set a more reasonable timeout for calculating the initial seed. The reference manuals says that "The initial seed takes approximately 2,000,000 clock cycles." The rngc peripheral clock runs at >= 33.25MHz, so seeding takes at most 60ms. A timeout of 200ms is more appropriate than the current value of 3 seconds. Signed-off-by: Martin Kaiser --- drivers/char/hw_random/imx-rngc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c index 127c292dfbbf..118a72acb99b 100644 --- a/drivers/char/hw_random/imx-rngc.c +++ b/drivers/char/hw_random/imx-rngc.c @@ -51,9 +51,8 @@ #define RNGC_ERROR_STATUS_STAT_ERR 0x00000008 -#define RNGC_TIMEOUT 3000 /* 3 sec */ - #define RNGC_SELFTEST_TIMEOUT 2500 /* us */ +#define RNGC_SEED_TIMEOUT 200 /* ms */ static bool self_test = true; module_param(self_test, bool, 0); @@ -184,7 +183,8 @@ static int imx_rngc_init(struct hwrng *rng) cmd = readl(rngc->base + RNGC_COMMAND); writel(cmd | RNGC_CMD_SEED, rngc->base + RNGC_COMMAND); - ret = wait_for_completion_timeout(&rngc->rng_op_done, msecs_to_jiffies(RNGC_TIMEOUT)); + ret = wait_for_completion_timeout(&rngc->rng_op_done, + msecs_to_jiffies(RNGC_SEED_TIMEOUT)); if (!ret) { ret = -ETIMEDOUT; goto err;