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 phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5519BC4332F for ; Sun, 4 Dec 2022 12:37:27 +0000 (UTC) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 159D4852C2; Sun, 4 Dec 2022 13:37:25 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="NdXkxLex"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 81294852D5; Sun, 4 Dec 2022 13:37:23 +0100 (CET) Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id 1E309852B1 for ; Sun, 4 Dec 2022 13:37:21 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=pali@kernel.org 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 ams.source.kernel.org (Postfix) with ESMTPS id ABD84B8091A; Sun, 4 Dec 2022 12:37:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CDC0C433D7; Sun, 4 Dec 2022 12:37:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670157439; bh=V9sPz2iTVh0f6QSNGdXbR9xvIuyZW3gMB1i157fK3Zw=; h=From:To:Cc:Subject:Date:From; b=NdXkxLexXsEFL7qzVolnfEzr8wBvt20LpvxDgGukwo0U7T7Px9pSxZmCF5H9uSUaa B+TeJlSVktuVbEdDGxUtyDU5GlbkyMXATVxw0rRMQ0A0UZKLgi6wiuF1AEqBTPrATo YCaf1doZp0+RMfWuYlNm6EJMnRa013rNQusN+dgpCGQ57xewjuNtyreA+m3jjg99pD LQ4YSXL0c24TE9vBYNZ493CJ7eRl9rgDehrDlPriAWTWWrcgslQuxufxQ9ZJYq5Jqi DVDGb594Lcj4QrZiqdM9MmKw6MOW+W0GQ3vp9wXwZy9BuZ4Wt2w/BXCRPDKzGwX94a 73Vr97cr47Rmg== Received: by pali.im (Postfix) id 8F553895; Sun, 4 Dec 2022 13:37:16 +0100 (CET) From: =?UTF-8?q?Pali=20Roh=C3=A1r?= To: Stefan Roese Cc: u-boot@lists.denx.de, Simon Glass Subject: [PATCH] serial: Use -EAGAIN in getc and putc Date: Sun, 4 Dec 2022 13:36:55 +0100 Message-Id: <20221204123655.29939-1-pali@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.39 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean U-Boot serial code already handles -EAGAIN value from getc and putc callbacks. So change drivers code to return -EAGAIN when HW is busy instead of doing its own busy loop and waiting until HW is ready. Signed-off-by: Pali Rohár --- drivers/serial/serial_arc.c | 8 ++++---- drivers/serial/serial_lpuart.c | 8 ++++---- drivers/serial/serial_mvebu_a3700.c | 8 ++++---- 3 files changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/serial/serial_arc.c b/drivers/serial/serial_arc.c index b2d95bdbe18d..c2fc8a901e25 100644 --- a/drivers/serial/serial_arc.c +++ b/drivers/serial/serial_arc.c @@ -53,8 +53,8 @@ static int arc_serial_putc(struct udevice *dev, const char c) struct arc_serial_plat *plat = dev_get_plat(dev); struct arc_serial_regs *const regs = plat->reg; - while (!(readb(®s->status) & UART_TXEMPTY)) - ; + if (!(readb(®s->status) & UART_TXEMPTY)) + return -EAGAIN; writeb(c, ®s->data); @@ -83,8 +83,8 @@ static int arc_serial_getc(struct udevice *dev) struct arc_serial_plat *plat = dev_get_plat(dev); struct arc_serial_regs *const regs = plat->reg; - while (!arc_serial_tstc(regs)) - ; + if (!arc_serial_tstc(regs)) + return -EAGAIN; /* Check for overflow errors */ if (readb(®s->status) & UART_OVERFLOW_ERR) diff --git a/drivers/serial/serial_lpuart.c b/drivers/serial/serial_lpuart.c index ff576da516d4..d7259d531b55 100644 --- a/drivers/serial/serial_lpuart.c +++ b/drivers/serial/serial_lpuart.c @@ -168,8 +168,8 @@ static void _lpuart_serial_setbrg(struct udevice *dev, static int _lpuart_serial_getc(struct lpuart_serial_plat *plat) { struct lpuart_fsl *base = plat->reg; - while (!(__raw_readb(&base->us1) & (US1_RDRF | US1_OR))) - schedule(); + if (!(__raw_readb(&base->us1) & (US1_RDRF | US1_OR))) + return -EAGAIN; barrier(); @@ -181,8 +181,8 @@ static void _lpuart_serial_putc(struct lpuart_serial_plat *plat, { struct lpuart_fsl *base = plat->reg; - while (!(__raw_readb(&base->us1) & US1_TDRE)) - schedule(); + if (!(__raw_readb(&base->us1) & US1_TDRE)) + return -EAGAIN; __raw_writeb(c, &base->ud); } diff --git a/drivers/serial/serial_mvebu_a3700.c b/drivers/serial/serial_mvebu_a3700.c index 0fcd7e88acee..b2017c645565 100644 --- a/drivers/serial/serial_mvebu_a3700.c +++ b/drivers/serial/serial_mvebu_a3700.c @@ -40,8 +40,8 @@ static int mvebu_serial_putc(struct udevice *dev, const char ch) struct mvebu_plat *plat = dev_get_plat(dev); void __iomem *base = plat->base; - while (readl(base + UART_STATUS_REG) & UART_STATUS_TXFIFO_FULL) - ; + if (readl(base + UART_STATUS_REG) & UART_STATUS_TXFIFO_FULL) + return -EAGAIN; writel(ch, base + UART_TX_REG); @@ -53,8 +53,8 @@ static int mvebu_serial_getc(struct udevice *dev) struct mvebu_plat *plat = dev_get_plat(dev); void __iomem *base = plat->base; - while (!(readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)) - ; + if (!(readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)) + return -EAGAIN; return readl(base + UART_RX_REG) & 0xff; } -- 2.20.1