From patchwork Sat Dec 10 23:31:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 1714519 X-Patchwork-Delegate: trini@ti.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.denx.de (client-ip=2a01:238:438b:c500:173d:9f52:ddab:ee01; helo=phobos.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=a/8EcZ4I; dkim-atps=neutral Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4NV40n4CkRz23pD for ; Sun, 11 Dec 2022 10:31:53 +1100 (AEDT) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 16C3685369; Sun, 11 Dec 2022 00:31:48 +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="a/8EcZ4I"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 2798785369; Sun, 11 Dec 2022 00:31:47 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on phobos.denx.de X-Spam-Level: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.2 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 D89FF852FB for ; Sun, 11 Dec 2022 00:31:43 +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 8C86FB807E9; Sat, 10 Dec 2022 23:31:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEB8FC433D2; Sat, 10 Dec 2022 23:31:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670715102; bh=tVBWRtk62CocnaGDQ/zko3t+A6RFWbFkzeDytJtulHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a/8EcZ4IgKNkKAPg1KPPgYXaUE5mOIPSqAyYkHuwNZJy2Mi2onwsdm/ovnFe1u087 rmwTEC4PHStBKXKzrUT6JwnJ5FAtbborGBsmEss98vgxW2QTBtZzOYAkjLMgLJHoE/ 4krWIuG+FTEGWj+2dcDLLVBxFE9dRVjzLdAWGjZWeo9l35mF7oymGHfiudEANanVUx HddaHeTVkw6jL6btzcgOL76ZnYpPgAg5JhkEiCsPGxMtKAMCFMb0+vQnrPcQ4qTud7 /JvEPsx/ndG92udHFNWA0GQ+ixW52mNTrdulRgxVHihcHX3gActXz2oVa3cnqI95LA J8fP4LYQsdqlA== Received: by pali.im (Postfix) id 51DD497E; Sun, 11 Dec 2022 00:31:39 +0100 (CET) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Stefan Roese , Simon Glass , Tom Rini Cc: u-boot@lists.denx.de Subject: [PATCH v2] serial: Use -EAGAIN in getc and putc Date: Sun, 11 Dec 2022 00:31:21 +0100 Message-Id: <20221210233121.16066-1-pali@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20221204123655.29939-1-pali@kernel.org> References: <20221204123655.29939-1-pali@kernel.org> MIME-Version: 1.0 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 --- Changes in v2: * Fix serial_lpuart.c code after Tom's review * Add serial_mpc8xx.c change To prevent merge conflicts, please apply this patch *after* this: http://patchwork.ozlabs.org/project/uboot/patch/20221210232744.15600-1-pali@kernel.org/ --- drivers/serial/serial_arc.c | 8 +++---- drivers/serial/serial_lpuart.c | 36 ++++++++++++----------------- drivers/serial/serial_mpc8xx.c | 12 ++++------ drivers/serial/serial_mvebu_a3700.c | 8 +++---- 4 files changed, 28 insertions(+), 36 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 07941c29ed74..51e66abdbc15 100644 --- a/drivers/serial/serial_lpuart.c +++ b/drivers/serial/serial_lpuart.c @@ -168,23 +168,24 @@ 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(); return __raw_readb(&base->ud); } -static void _lpuart_serial_putc(struct lpuart_serial_plat *plat, +static int _lpuart_serial_putc(struct lpuart_serial_plat *plat, const char c) { 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); + return 0; } /* Test whether a character is in the RX buffer */ @@ -328,10 +329,9 @@ static int _lpuart32_serial_getc(struct lpuart_serial_plat *plat) u32 stat, val; lpuart_read32(plat->flags, &base->stat, &stat); - while ((stat & STAT_RDRF) == 0) { + if ((stat & STAT_RDRF) == 0) { lpuart_write32(plat->flags, &base->stat, STAT_FLAGS); - schedule(); - lpuart_read32(plat->flags, &base->stat, &stat); + return -EAGAIN; } lpuart_read32(plat->flags, &base->data, &val); @@ -343,22 +343,18 @@ static int _lpuart32_serial_getc(struct lpuart_serial_plat *plat) return val & 0x3ff; } -static void _lpuart32_serial_putc(struct lpuart_serial_plat *plat, +static int _lpuart32_serial_putc(struct lpuart_serial_plat *plat, const char c) { struct lpuart_fsl_reg32 *base = plat->reg; u32 stat; - while (true) { - lpuart_read32(plat->flags, &base->stat, &stat); - - if ((stat & STAT_TDRE)) - break; - - schedule(); - } + lpuart_read32(plat->flags, &base->stat, &stat); + if (!(stat & STAT_TDRE)) + return -EAGAIN; lpuart_write32(plat->flags, &base->data, c); + return 0; } /* Test whether a character is in the RX buffer */ @@ -453,11 +449,9 @@ static int lpuart_serial_putc(struct udevice *dev, const char c) struct lpuart_serial_plat *plat = dev_get_plat(dev); if (is_lpuart32(dev)) - _lpuart32_serial_putc(plat, c); - else - _lpuart_serial_putc(plat, c); + return _lpuart32_serial_putc(plat, c); - return 0; + return _lpuart_serial_putc(plat, c); } static int lpuart_serial_pending(struct udevice *dev, bool input) diff --git a/drivers/serial/serial_mpc8xx.c b/drivers/serial/serial_mpc8xx.c index 808a40f503ea..b8d6a81b650f 100644 --- a/drivers/serial/serial_mpc8xx.c +++ b/drivers/serial/serial_mpc8xx.c @@ -178,14 +178,13 @@ static int serial_mpc8xx_putc(struct udevice *dev, const char c) rtx = (struct serialbuffer __iomem *)&cpmp->cp_dpmem[CPM_SERIAL_BASE]; - /* Wait for last character to go. */ + if (in_be16(&rtx->txbd.cbd_sc) & BD_SC_READY) + return -EAGAIN; + out_8(&rtx->txbuf, c); out_be16(&rtx->txbd.cbd_datlen, 1); setbits_be16(&rtx->txbd.cbd_sc, BD_SC_READY); - while (in_be16(&rtx->txbd.cbd_sc) & BD_SC_READY) - schedule(); - return 0; } @@ -199,9 +198,8 @@ static int serial_mpc8xx_getc(struct udevice *dev) rtx = (struct serialbuffer __iomem *)&cpmp->cp_dpmem[CPM_SERIAL_BASE]; - /* Wait for character to show up. */ - while (in_be16(&rtx->rxbd.cbd_sc) & BD_SC_EMPTY) - schedule(); + if (in_be16(&rtx->rxbd.cbd_sc) & BD_SC_EMPTY) + return -EAGAIN; /* the characters are read one by one, * use the rxindex to know the next char to deliver 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; }