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 3A4F2C4332F for ; Tue, 15 Nov 2022 16:00:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231158AbiKOQAZ (ORCPT ); Tue, 15 Nov 2022 11:00:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229533AbiKOQAW (ORCPT ); Tue, 15 Nov 2022 11:00:22 -0500 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8A83F0; Tue, 15 Nov 2022 08:00:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668528020; x=1700064020; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=EQtU8zLO0gwSoon26zbo9hDeoJ1iuGf+W9YAIqhY6lk=; b=SjWvmltF35yCVVxpClKjYOY1F9RYcJFeG5cUfUE7afUVuGq7XTgJgOOd 0NkcZnV3cBENxvDC8PooqjFg8vpZqE0A1mYNIceA0GiQu0WOlrXv7Gaxp GO0C8Y65Q5gcDDJLBCPxzVGepb838nWY7TBTrfsWQtUe5Kp0UABJsmma2 nWv+ppYlwa/tlzycxBocWPx17PIkgS+jnZcAEaoXD9hYprGRrr/0X+dB5 3e/cqac4Hmhs4im7MuQ6J40uyvym3zUGKixoh95eM0b7Qg3J4gbWQWIUI /5/sM5ZXSpBVKu0taAVQlJwmvb4fL2afxxF5M64xOl+R5neCPe3U5hwtC g==; X-IronPort-AV: E=McAfee;i="6500,9779,10532"; a="291997887" X-IronPort-AV: E=Sophos;i="5.96,166,1665471600"; d="scan'208";a="291997887" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Nov 2022 08:00:17 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10532"; a="707780960" X-IronPort-AV: E=Sophos;i="5.96,166,1665471600"; d="scan'208";a="707780960" Received: from mrosso-mobl1.ger.corp.intel.com ([10.249.45.244]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Nov 2022 08:00:13 -0800 Date: Tue, 15 Nov 2022 18:00:11 +0200 (EET) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: Gabriel Somlo cc: LKML , linux-serial , Greg Kroah-Hartman , Jiri Slaby , kgugala@antmicro.com, mholenko@antmicro.com, joel@jms.id.au, david.abdurachmanov@gmail.com, florent@enjoy-digital.fr, geert@linux-m68k.org Subject: Re: [PATCH v3 12/14] serial: liteuart: add IRQ support for the RX path In-Reply-To: <20221112212125.448824-13-gsomlo@gmail.com> Message-ID: References: <20221112212125.448824-1-gsomlo@gmail.com> <20221112212125.448824-13-gsomlo@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 12 Nov 2022, Gabriel Somlo wrote: > Add support for IRQ-driven RX. Support for the TX path will be added > in a separate commit. > > Signed-off-by: Gabriel Somlo > --- > drivers/tty/serial/liteuart.c | 61 +++++++++++++++++++++++++++++++---- > 1 file changed, 54 insertions(+), 7 deletions(-) > > diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c > index cf1ce597b45e..e30adb30277f 100644 > --- a/drivers/tty/serial/liteuart.c > +++ b/drivers/tty/serial/liteuart.c > @@ -6,6 +6,7 @@ > */ > > #include > +#include > #include > #include > #include > @@ -130,13 +131,29 @@ static void liteuart_rx_chars(struct uart_port *port) > tty_flip_buffer_push(&port->state->port); > } > > +static irqreturn_t liteuart_interrupt(int irq, void *data) > +{ > + struct liteuart_port *uart = data; > + struct uart_port *port = &uart->port; > + u8 isr = litex_read8(port->membase + OFF_EV_PENDING); > + > + /* for now, only rx path triggers interrupts */ Please don't add comment like this at all when your series removes it in a later patch. > + isr &= EV_RX; > + > + spin_lock(&port->lock); > + if (isr & EV_RX) > + liteuart_rx_chars(port); > + spin_unlock(&port->lock); > + > + return IRQ_RETVAL(isr); > +} > + > static void liteuart_timer(struct timer_list *t) > { > struct liteuart_port *uart = from_timer(uart, t, timer); > struct uart_port *port = &uart->port; > > - liteuart_rx_chars(port); > - > + liteuart_interrupt(0, port); > mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); > } > > @@ -162,19 +179,42 @@ static unsigned int liteuart_get_mctrl(struct uart_port *port) > static int liteuart_startup(struct uart_port *port) > { > struct liteuart_port *uart = to_liteuart_port(port); > + int ret; > + u8 irq_mask = 0; > > - /* disable events */ > - litex_write8(port->membase + OFF_EV_ENABLE, 0); > + if (port->irq) { > + ret = request_irq(port->irq, liteuart_interrupt, 0, > + KBUILD_MODNAME, uart); > + if (ret == 0) { > + /* only enable rx interrupts at this time */ This comment seems pretty useless. Your code says very much the same. -- i. > + irq_mask = EV_RX; > + } else { > + pr_err(pr_fmt("line %d irq %d failed: using polling\n"), > + port->line, port->irq); > + port->irq = 0; > + } > + } > > - /* prepare timer for polling */ > - timer_setup(&uart->timer, liteuart_timer, 0); > - mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); > + if (!port->irq) { > + timer_setup(&uart->timer, liteuart_timer, 0); > + mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); > + } > + > + litex_write8(port->membase + OFF_EV_ENABLE, irq_mask); > > return 0; > } > > static void liteuart_shutdown(struct uart_port *port) > { > + struct liteuart_port *uart = to_liteuart_port(port); > + > + litex_write8(port->membase + OFF_EV_ENABLE, 0); > + > + if (port->irq) > + free_irq(port->irq, port); > + else > + del_timer_sync(&uart->timer); > } > > static void liteuart_set_termios(struct uart_port *port, struct ktermios *new, > @@ -263,6 +303,13 @@ static int liteuart_probe(struct platform_device *pdev) > goto err_erase_id; > } > > + /* get irq */ > + ret = platform_get_irq_optional(pdev, 0); > + if (ret < 0 && ret != -ENXIO) > + return ret; > + if (ret > 0) > + port->irq = ret; > + > /* values not from device tree */ > port->dev = &pdev->dev; > port->iotype = UPIO_MEM; >