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 0C8F2C4332F for ; Tue, 15 Nov 2022 16:21:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230095AbiKOQVI (ORCPT ); Tue, 15 Nov 2022 11:21:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230034AbiKOQVH (ORCPT ); Tue, 15 Nov 2022 11:21:07 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21F1210C3; Tue, 15 Nov 2022 08:21:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668529266; x=1700065266; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=JfTC8m8Q4FYXgVJlchjlzdhxCWxzzUXbMBu2VN/q2cQ=; b=RRpAxpfTNlmRBFrlJWhrUdM2JgkQPCYFnbgweo7uLuH7sbgNi3p5Zg10 r7X9TDCfww/vjztiLDCHmBrbOofBlWVYc/RfIAB1WP0YXd/HNaYcQP3Up scDNb5DdgsKzbcP7xXeWspyiv2QsGWoqRCgIphIph/NeWaKOohaamH9GB QlNBUhKpCknloqIT4/Sq2zR7bmbhNVDAt5yBaN4km8OLE0UtQZMBY8A29 nwCHL3tLiYMKrisqY6+hyGekQEcdauavWRocRhymuGsVe6vEsuQKuXhgV QSR50bLFiOEXfijXCY9QcpIk5RvddnlE0kJSPcjYfueSJ056rrRpl5hlH A==; X-IronPort-AV: E=McAfee;i="6500,9779,10532"; a="398584148" X-IronPort-AV: E=Sophos;i="5.96,166,1665471600"; d="scan'208";a="398584148" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Nov 2022 08:21:05 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10532"; a="707791440" X-IronPort-AV: E=Sophos;i="5.96,166,1665471600"; d="scan'208";a="707791440" 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 08:21:01 -0800 Date: Tue, 15 Nov 2022 18:21:00 +0200 (EET) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: "Gabriel L. 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: Message-ID: <7b5042be-8061-d4f4-43b5-75a5ad6dbcb0@linux.intel.com> References: <20221112212125.448824-1-gsomlo@gmail.com> <20221112212125.448824-13-gsomlo@gmail.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-155084183-1668529265=:2268" Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-155084183-1668529265=:2268 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT On Tue, 15 Nov 2022, Gabriel L. Somlo wrote: > On Tue, Nov 15, 2022 at 06:00:11PM +0200, Ilpo Järvinen wrote: > > 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. > > OK, I will remove it in v4. > > > > + 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. > > The comment was meant to let the reader know that the code is doing it > *intentionally* (rather than forgetting to enable tx irqs by mistake). > But I'm OK with removing this comment in v4 as well if you think > that's an overly paranoid and redundant thing to do... :) I see. Reading the other comment first caused me to misinterpret this one to mean that only RX interrupts are implemented. Maybe if you change "at this time" to "at startup" it would make it more obvious. -- i. --8323329-155084183-1668529265=:2268--