From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ECFEB1ABED9; Wed, 8 Jul 2026 06:03:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783490591; cv=none; b=k4gUpWOvtvhOveM5F+6o27WrB7p4qUHHbL55Lvi38K1LFR4hbak6m+i1xb572VZ6b2kHnaNZXHs0PC+ivbZ+bemk1wGT5NxO2BmNv7RNQnI/ABXl0qgzshsBTkouGvMUiPy0hzWsOG5JD6MwVdCAhIIMD3LguACuJtFjHkFq9SY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783490591; c=relaxed/simple; bh=gSKIrVdgDbhsjTT7Fwbx/W0AdkIDbkQRquzcDz2U2OU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jh0iBGTWMCJre3gm4Jrs39cXMIN3629DTpnhUTv6zMwT6gqtDqmgFrXJ3sVhRWUhuDsKVSnHKI2rNaN+YdRK0CHirkeHu4hFFE46TO+eMR/QgvDQ1k5gY/ATAzaMdYjtjsg9J9NIpNaQRLwpyBcpFOl4ruYo5z45UuAX0UMkqtY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VS1igjd+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VS1igjd+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28F071F000E9; Wed, 8 Jul 2026 06:03:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783490589; bh=Fj0iGrfuPytQrb9kpP8/968TUDgqCaTRyYSgg+8fF50=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=VS1igjd+3YmBZqpEuQoiMIY5jWsl1riPbUXso0rwL+OMjlUUIU+30bmzLg2xDhivU HcCwgb9O/Lm3a5hMot8aOkDOvxO2YIKXk/FO9zlsuVYRhplNgGYLkFLGkEf8X8P4Ye U2XlpF2qg3YG65tJflmLZy/qYkmweh7gWW+qxlhJeQdBc2pDtLtB85D9OBiTMSoKGV Ggd+0rTSq9gj/w/dTgtXLiwvedzaeKNvKGtZ+Evf6g84Qa1+QbR8AbOiPnrhLkWl24 V95QPPWHbjJFv7j3506pyO4STg9/jYAQKh48Nz2TMKWkrPxhkqm4PjmDegChUsWBq9 5xkqaqIbTcYsg== Message-ID: <25599a7f-e9cb-4aa0-a375-d9b4ed52be5e@kernel.org> Date: Wed, 8 Jul 2026 08:03:04 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] serial: 8250: fix shared IRQ startup race causing IRQ warning To: Wang Zhaolong , gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, andriy.shevchenko@linux.intel.com, albanhuang@tencent.com, tombinfan@tencent.com, jackzxcui1989@163.com, kees@kernel.org, osama.abdelkader@gmail.com, realwujing@gmail.com References: <20260527092052.2086342-1-wangzhaolong@fnnas.com> <20260708031115.3757150-1-wangzhaolong@fnnas.com> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Ah, you are fixing the same thing as: https://lore.kernel.org/all/20260707-bug-221579-8250-shared-irq-race-v6-1-f8c499a90bdd@gmail.com/ I did not look up who of you was first. Note the above contains you in the commit log: Reported-by: Wang Zhaolong Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221579 You both CCed each other, so you know the other's submission. I don't understand why you both send the patch? Anyway, you guys speak to each other and decide who sends the (fixed) patch. On 08. 07. 26, 5:11, Wang Zhaolong wrote: ... > --- a/drivers/tty/serial/8250/8250_core.c > +++ b/drivers/tty/serial/8250/8250_core.c > @@ -154,10 +152,18 @@ static struct irq_info *serial_get_or_create_irq_info(const struct uart_8250_por > static int serial_link_irq_chain(struct uart_8250_port *up) > { > struct irq_info *i; > int ret; > > + /* > + * Keep the hash lock held until the first request_irq() completes. > + * The first port publishes i->head before request_irq() starts the IRQ; > + * a second port sharing the IRQ must not join the chain and run the > + * THRE test while the IRQ core is still bringing the line up. > + */ > + guard(mutex)(&hash_mutex); The same as in the other patch: hash_mutex is no longer an appropriate name for this lock. > + > i = serial_get_or_create_irq_info(up); > if (IS_ERR(i)) > return PTR_ERR(i); > > scoped_guard(spinlock_irq, &i->lock) { thanks, -- js suse labs