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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98021C43217 for ; Tue, 5 Apr 2022 23:52:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1580780AbiDEXeu (ORCPT ); Tue, 5 Apr 2022 19:34:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356057AbiDEKWu (ORCPT ); Tue, 5 Apr 2022 06:22:50 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C99DAF1E9; Tue, 5 Apr 2022 03:05:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9C14E6167E; Tue, 5 Apr 2022 10:05:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB82CC385A2; Tue, 5 Apr 2022 10:05:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649153143; bh=68aLZg2k8y7k/NuHYgwWso1X6n6Cr9BCaz8zPh9HeQ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d/ApYtfnojLm0fPOSp6NvHaprXjioGcuSxcTM78kLxX3hKcZ+tT5uRDwR4I7hbsHn 8jEYcgiL2C3Tp1J8y+Xs/taAHK8XnrZVnUQCf0VCV1zKuog5j6Dj3nZsgt8Kce1FVF G2kErwxHR9KlFTb3nCGTFFjtjr4UcpN4Q5xRv3UI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?=D0=9C=D0=B8=D1=85=D0=B0=D0=B8=D0=BB?= , Sean Young , Mauro Carvalho Chehab Subject: [PATCH 5.10 115/599] media: gpio-ir-tx: fix transmit with long spaces on Orange Pi PC Date: Tue, 5 Apr 2022 09:26:49 +0200 Message-Id: <20220405070302.261443204@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070258.802373272@linuxfoundation.org> References: <20220405070258.802373272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Young commit 5ad05ecad4326ddaa26a83ba2233a67be24c1aaa upstream. Calling udelay for than 1000us does not always yield the correct results. Cc: stable@vger.kernel.org Reported-by: Михаил Signed-off-by: Sean Young Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/rc/gpio-ir-tx.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) --- a/drivers/media/rc/gpio-ir-tx.c +++ b/drivers/media/rc/gpio-ir-tx.c @@ -48,11 +48,29 @@ static int gpio_ir_tx_set_carrier(struct return 0; } +static void delay_until(ktime_t until) +{ + /* + * delta should never exceed 0.5 seconds (IR_MAX_DURATION) and on + * m68k ndelay(s64) does not compile; so use s32 rather than s64. + */ + s32 delta; + + while (true) { + delta = ktime_us_delta(until, ktime_get()); + if (delta <= 0) + return; + + /* udelay more than 1ms may not work */ + delta = min(delta, 1000); + udelay(delta); + } +} + static void gpio_ir_tx_unmodulated(struct gpio_ir *gpio_ir, uint *txbuf, uint count) { ktime_t edge; - s32 delta; int i; local_irq_disable(); @@ -63,9 +81,7 @@ static void gpio_ir_tx_unmodulated(struc gpiod_set_value(gpio_ir->gpio, !(i % 2)); edge = ktime_add_us(edge, txbuf[i]); - delta = ktime_us_delta(edge, ktime_get()); - if (delta > 0) - udelay(delta); + delay_until(edge); } gpiod_set_value(gpio_ir->gpio, 0); @@ -97,9 +113,7 @@ static void gpio_ir_tx_modulated(struct if (i % 2) { // space edge = ktime_add_us(edge, txbuf[i]); - delta = ktime_us_delta(edge, ktime_get()); - if (delta > 0) - udelay(delta); + delay_until(edge); } else { // pulse ktime_t last = ktime_add_us(edge, txbuf[i]);