From patchwork Thu Aug 24 19:20:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Kaiser X-Patchwork-Id: 716638 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 30025C88CB9 for ; Thu, 24 Aug 2023 19:24:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243171AbjHXTYI (ORCPT ); Thu, 24 Aug 2023 15:24:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243164AbjHXTXv (ORCPT ); Thu, 24 Aug 2023 15:23:51 -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 EFB731BEB; Thu, 24 Aug 2023 12:23:48 -0700 (PDT) Received: from dslb-188-097-211-187.188.097.pools.vodafone-ip.de ([188.97.211.187] 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 1qZFvj-00036P-5D; Thu, 24 Aug 2023 21:23:43 +0200 From: Martin Kaiser To: Herbert Xu Cc: Alexander Stein , linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Martin Kaiser Subject: [PATCH v2 2/6] hwrng: imx-rngc - reasonable timeout for initial seed Date: Thu, 24 Aug 2023 21:20:55 +0200 Message-Id: <20230824192059.1569591-3-martin@kaiser.cx> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230824192059.1569591-1-martin@kaiser.cx> References: <20230824192059.1569591-1-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." If the rngc peripheral clock runs at 66.5MHz, this is approx. 30ms. A timeout of 100ms is more appropriate that the current value of 3 seconds. We define the timeout in us to simplify the transition to readl_poll_timeout. Signed-off-by: Martin Kaiser --- v2: - adjust timeouts before we switch to polling drivers/char/hw_random/imx-rngc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c index 6024c923b67d..8ff3d46674fd 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 1500 /* us */ +#define RNGC_SELFTEST_TIMEOUT 1500 /* us */ +#define RNGC_SEED_TIMEOUT 100000 /* us */ 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, + usecs_to_jiffies(RNGC_SEED_TIMEOUT)); if (!ret) { ret = -ETIMEDOUT; goto err;