From patchwork Thu Aug 24 19:20:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Kaiser X-Patchwork-Id: 716950 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 442E0C88CB2 for ; Thu, 24 Aug 2023 19:24:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243166AbjHXTYI (ORCPT ); Thu, 24 Aug 2023 15:24:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243158AbjHXTXv (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 EFBBF1BEC; 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-Ud; Thu, 24 Aug 2023 21:23:44 +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 3/6] hwrng: imx-rngc - use polling to detect end of self test Date: Thu, 24 Aug 2023 21:20:56 +0200 Message-Id: <20230824192059.1569591-4-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 Use polling to detect the end of the rngc self test. This is much simpler than using an interrupt and a completion. The selftest should take approx. 450us. Keep the overhead to a minimum by polling every 500us. (We've already lowered the timeout to 1.5ms.) Signed-off-by: Martin Kaiser --- v2: - use shorter timeout and polling interval drivers/char/hw_random/imx-rngc.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c index 8ff3d46674fd..09523936d2af 100644 --- a/drivers/char/hw_random/imx-rngc.c +++ b/drivers/char/hw_random/imx-rngc.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #define RNGC_VER_ID 0x0000 @@ -101,22 +102,19 @@ static inline void imx_rngc_irq_unmask(struct imx_rngc *rngc) static int imx_rngc_self_test(struct imx_rngc *rngc) { - u32 cmd; + u32 cmd, status; int ret; - imx_rngc_irq_unmask(rngc); - /* run self test */ cmd = readl(rngc->base + RNGC_COMMAND); writel(cmd | RNGC_CMD_SELF_TEST, rngc->base + RNGC_COMMAND); - ret = wait_for_completion_timeout(&rngc->rng_op_done, - usecs_to_jiffies(RNGC_SELFTEST_TIMEOUT)); - imx_rngc_irq_mask_clear(rngc); - if (!ret) - return -ETIMEDOUT; + ret = readl_poll_timeout(rngc->base + RNGC_STATUS, status, + status & RNGC_STATUS_ST_DONE, 500, RNGC_SELFTEST_TIMEOUT); + if (ret < 0) + return ret; - return rngc->err_reg ? -EIO : 0; + return readl(rngc->base + RNGC_ERROR) ? -EIO : 0; } static int imx_rngc_read(struct hwrng *rng, void *data, size_t max, bool wait)