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 3351BC433FE for ; Fri, 18 Nov 2022 14:39:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241616AbiKROj2 (ORCPT ); Fri, 18 Nov 2022 09:39:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242346AbiKROjB (ORCPT ); Fri, 18 Nov 2022 09:39:01 -0500 Received: from mail-qk1-x72f.google.com (mail-qk1-x72f.google.com [IPv6:2607:f8b0:4864:20::72f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 32E2F9DBB0; Fri, 18 Nov 2022 06:36:19 -0800 (PST) Received: by mail-qk1-x72f.google.com with SMTP id x18so3499832qki.4; Fri, 18 Nov 2022 06:36:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=3yNekkaM54IBN/9Il9peqkckszMXJVwQO0bvHskjSXg=; b=pBx0nyYS46s2eCNgZV+XuzvhqDvKHPVb0dYdTm7GNB8p2Kk7LDlWV+/zxnQutGVhdR UWKxD5pKTlJjeoj9mmG0xrSHM2t8izVTvGxBFYa64aUn1b00FftRdgajB6iTYfZwMF7v y8ssKjNERYa/Pn56fzSiav/mxTT/rSm2zNzU/DPpBDoGboeEogBltLGainINnpuK6CpB znrKQegbWqa1drG933n7d9sfLpAfSyECyzARPmZZK2/kmapkC8mga0dKTz7DD3YN28Gy KX7wm6xWSmMqqQkEzQfHgz7g7+LJ9gcnP7SyFS44WpHdD1Oo8Ct2+ocHaIymkfahgKV5 6sIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3yNekkaM54IBN/9Il9peqkckszMXJVwQO0bvHskjSXg=; b=iqfpZW64qp68bxwad57/m6eVToiidysB0G0WGpH/OcTa5gmrsvDCFFEcZPhemPmtYd x1ORBAHAc7aGM9z6b+PuU6sr0NZtbRObbDkeQC8w13v+t+/aH+MNWnI6ygZjkqeldC+A UZuyir5V8yksao7xkZCcg6rybWFehjRbMcwjnsEH5mVQk6mm/KeIbZ+5BUH1P4gcXx4Q YEH6sma/uYXIogZsU9hF/SCrVUj6On2rQMNBR9+/hO1Yvfp+xjPA6srhkJBGgTFcPKho wzU+f8Olun3v+u0cGkP/qhYKeSCnYqhc49zzT8N7tcBP7GaWTf4N8P8jBjNqbkkhLWUd jMkw== X-Gm-Message-State: ANoB5pldjKuT5wTHvnKmZowrQBT2Z93n4R5MViLSBRusnpg+G2/O9dP/ eEd7BX8LpsgUyXOE2cfwYMuyI67695yvfA== X-Google-Smtp-Source: AA0mqf7OElkmp/26mL7Aw84NQIYM21B4YcIiqkJoW4p3zmlYfnCqqHSq+Cnyb38r18TTfazyH1bK3w== X-Received: by 2002:a05:620a:a10:b0:6fb:a7e6:96e with SMTP id i16-20020a05620a0a1000b006fba7e6096emr5809001qka.675.1668782178103; Fri, 18 Nov 2022 06:36:18 -0800 (PST) Received: from errol.ini.cmu.edu (pool-72-77-81-136.pitbpa.fios.verizon.net. [72.77.81.136]) by smtp.gmail.com with ESMTPSA id f13-20020a05620a408d00b006bb78d095c5sm2524453qko.79.2022.11.18.06.36.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Nov 2022 06:36:17 -0800 (PST) Date: Fri, 18 Nov 2022 09:36:15 -0500 From: "Gabriel L. Somlo" To: Ilpo =?iso-8859-1?Q?J=E4rvinen?= 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 v4 12/14] serial: liteuart: add IRQ support for the RX path Message-ID: References: <20221116144908.234154-1-gsomlo@gmail.com> <20221116144908.234154-13-gsomlo@gmail.com> <6629539b-c5a7-4edc-7ab1-5c977f7319@linux.intel.com> <26f43d54-7ee6-d05e-5c1c-4bc37f06077@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <26f43d54-7ee6-d05e-5c1c-4bc37f06077@linux.intel.com> X-Clacks-Overhead: GNU Terry Pratchett Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 18, 2022 at 04:30:15PM +0200, Ilpo Järvinen wrote: > On Fri, 18 Nov 2022, Gabriel L. Somlo wrote: > > > On Fri, Nov 18, 2022 at 03:58:47PM +0200, Ilpo Järvinen wrote: > > > On Wed, 16 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 > > > > --- > > > > > > > > Changes from v3: > > > > - add shadow irq register to support polling mode and avoid reading > > > > hardware mmio irq register to learn which irq flags are enabled > > > > - this also simplifies both liteuart_interrupt() and liteuart_startup() > > > > > > > > drivers/tty/serial/liteuart.c | 76 +++++++++++++++++++++++++++++++---- > > > > 1 file changed, 69 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c > > > > index 8a6e176be08e..fad778578986 100644 > > > > --- a/drivers/tty/serial/liteuart.c > > > > +++ b/drivers/tty/serial/liteuart.c > > > > @@ -7,6 +7,7 @@ > > > > > > > > #include > > > > #include > > > > +#include > > > > #include > > > > #include > > > > #include > > > > @@ -46,6 +47,7 @@ struct liteuart_port { > > > > struct uart_port port; > > > > struct timer_list timer; > > > > u32 id; > > > > + u8 irq_reg; > > > > }; > > > > > > > > #define to_liteuart_port(port) container_of(port, struct liteuart_port, port) > > > > @@ -76,6 +78,19 @@ static void liteuart_putchar(struct uart_port *port, unsigned char ch) > > > > litex_write8(port->membase + OFF_RXTX, ch); > > > > } > > > > > > > > +static void liteuart_update_irq_reg(struct uart_port *port, bool set, u8 mask) > > > > +{ > > > > + struct liteuart_port *uart = to_liteuart_port(port); > > > > + > > > > + if (set) > > > > + uart->irq_reg |= mask; > > > > + else > > > > + uart->irq_reg &= ~mask; > > > > + > > > > + if (port->irq) > > > > + litex_write8(port->membase + OFF_EV_ENABLE, uart->irq_reg); > > > > +} > > > > + > > > > static void liteuart_stop_tx(struct uart_port *port) > > > > { > > > > } > > > > @@ -129,13 +144,27 @@ 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; > > > > + > > > > + spin_lock(&port->lock); > > > > + isr = litex_read8(port->membase + OFF_EV_PENDING) & uart->irq_reg; > > > > + 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)); > > > > } > > > > > > > > @@ -161,19 +190,45 @@ 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); > > > > + unsigned long flags; > > > > + int ret; > > > > > > > > - /* 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) { > > > > + pr_err(pr_fmt("line %d irq %d failed: using polling\n"), > > > > + port->line, port->irq); > > > > > > dev_err() seems more appropriate here. > > > > Makes sense, good thing `struct uart_port` has a `dev` field :) > > I've made the change, and lined it up for the upcoming v5 of the > > series. > > Also that pr_fmt() should be dropped (in case you didn't already). It was > in my mind ealier but should have stated it explicitly. Understood. I've used dev_err() before, it just slipped my mind to check for the availability of a `dev` field in `struct uart_port`... :) Thanks again for the review! Best, --Gabriel