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: 722274 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 88738CA0EEB for ; Tue, 12 Sep 2023 14:34:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236055AbjILOey (ORCPT ); Tue, 12 Sep 2023 10:34:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236047AbjILOeu (ORCPT ); Tue, 12 Sep 2023 10:34:50 -0400 Received: from viti.kaiser.cx (viti.kaiser.cx [IPv6:2a01:238:43fe:e600:cd0c:bd4a:7a3:8e9f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17B12CC3; Tue, 12 Sep 2023 07:34:46 -0700 (PDT) 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 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.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;