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 X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11422C10DCE for ; Wed, 18 Mar 2020 19:11:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E06842077A for ; Wed, 18 Mar 2020 19:11:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584558669; bh=i8/4x4L6BzJAkJGRo/v8prKLCHA1ASdllNL4i+xuPoM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=XU8mIZrvBrEAtbihqyUUMpBms+mYoPEkB4g6lnuMQ9LmQelU8SCcjdtrlXmG+1cqs ulsrVlG6vKH/L0fXsCR8XjMDnIiBXwivtrcI5/S2ntEBo5Q6T7FPgtJxm7Noc8+2lD ehTCjORaLa8anW3wwwURYys41JRlWvIRC+Ub9qf4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726997AbgCRTLI (ORCPT ); Wed, 18 Mar 2020 15:11:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:53466 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726623AbgCRTLI (ORCPT ); Wed, 18 Mar 2020 15:11:08 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6795320768; Wed, 18 Mar 2020 19:11:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584558667; bh=i8/4x4L6BzJAkJGRo/v8prKLCHA1ASdllNL4i+xuPoM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Dt0nHeg7Qcu0KW7uQbQ2qwUrNujsVAuLeAiJrrKBfvfGCVCeKWWsB3VlZn9e3qlsd QyqJnS9r2Z3UhO8B52td/QEWvjPisF6g94G9C+MWp7pHHwNHTABvj0mCKpZDUQqGSq HNXZA2KunSE7Uzunjz/1sR2GT5XB7FE8uNPWTvbY= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1jEe5p-00Diha-NV; Wed, 18 Mar 2020 19:11:05 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Wed, 18 Mar 2020 19:11:05 +0000 From: Marc Zyngier To: Sungbo Eo Cc: linux-oxnas@groups.io, Linus Walleij , Thomas Gleixner , Jason Cooper , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Neil Armstrong Subject: Re: [PATCH] irqchip/versatile-fpga: Handle chained IRQs properly In-Reply-To: References: <20200318170904.1461278-1-mans0n@gorani.run> <112cdab389aa9cc30189c7aec0baded2@kernel.org> Message-ID: <002b72cab9896fa5ac76a52e0cb503ff@kernel.org> X-Sender: maz@kernel.org User-Agent: Roundcube Webmail/1.3.10 X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: mans0n@gorani.run, linux-oxnas@groups.io, linus.walleij@linaro.org, tglx@linutronix.de, jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, narmstrong@baylibre.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-03-18 18:20, Sungbo Eo wrote: > Hi Marc, > > On 2020-03-19 02:48, Marc Zyngier wrote: >> Hi Sungbo, >> >> On 2020-03-18 17:09, Sungbo Eo wrote: >>> Enclose the chained handler with chained_irq_{enter,exit}(), so that >>> the >>> muxed interrupts get properly acked. >>> >>> This patch also fixes a reboot bug on OX820 SoC, where the jiffies >>> timer >>> interrupt is never acked. The kernel waits a clock tick forever in >>> calibrate_delay_converge(), which leads to a boot hang. >> >> Nice catch. >> >>> >>> Signed-off-by: Sungbo Eo >>> Cc: Neil Armstrong >>> --- >>>  drivers/irqchip/irq-versatile-fpga.c | 9 ++++++++- >>>  1 file changed, 8 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/irqchip/irq-versatile-fpga.c >>> b/drivers/irqchip/irq-versatile-fpga.c >>> index 928858dada75..08faab2fec3e 100644 >>> --- a/drivers/irqchip/irq-versatile-fpga.c >>> +++ b/drivers/irqchip/irq-versatile-fpga.c >>> @@ -6,6 +6,7 @@ >>>  #include >>>  #include >>>  #include >>> +#include >>>  #include >>>  #include >>>  #include >>> @@ -68,12 +69,15 @@ static void fpga_irq_unmask(struct irq_data *d) >>> >>>  static void fpga_irq_handle(struct irq_desc *desc) >>>  { >>> +    struct irq_chip *chip = irq_desc_get_chip(desc); >>>      struct fpga_irq_data *f = irq_desc_get_handler_data(desc); >>>      u32 status = readl(f->base + IRQ_STATUS); >>> >>> +    chained_irq_enter(chip, desc); >>> + >> >> It's probably not a big deal, but I'm not fond of starting talking to >> the muxing irqchip before having done the chained_irq_enter() call. >> >> Moving that read here would probably be safer. > > Oops, I missed it. Thanks for pointing it out. > >> >>>      if (status == 0) { >>>          do_bad_IRQ(desc); >>> -        return; >>> +        goto out; >>>      } >>> >>>      do { >>> @@ -82,6 +86,9 @@ static void fpga_irq_handle(struct irq_desc *desc) >>>          status &= ~(1 << irq); >>>          generic_handle_irq(irq_find_mapping(f->domain, irq)); >>>      } while (status); >>> + >>> +out: >>> +    chained_irq_exit(chip, desc); >>>  } >>> >>>  /* >> >> Otherwise looks good. If you send it again with the above fixed >> and a Fixes: tag, I'll queue it. > > It seems the handler had been broken from the very beginning. Could > you give me a hint on how the tag should be like? Indeed, it has been broken forever. I'm tempted to say: Fixes: c41b16f8c9d9d ("ARM: integrator/versatile: consolidate FPGA IRQ handling code") even if it probably predates the introduction of the chained_irq_enter() helpers. This will ensure this gets backported to older kernels... Thanks, M. -- Jazz is not dead. It just smells funny...