From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D60961D555; Fri, 20 Feb 2026 06:34:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771569245; cv=none; b=WahIVQI47Q55CSFc1udc8paWKMHCtZSwy9tHbFKwSc/JpZ0HDeBm2MF3iJVsD5Hc1K/Z/j523qEQ6JjsuoIlAznMgvHF72NMmViVq0G/hD4NkSfptcxlX81vjh20e5+53TH/nopO/+XihlD4+3xAFDFwl49aO3xAJudMwJFCS3Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771569245; c=relaxed/simple; bh=Ial17sfZgdVRiZ5JFwlMSLgTFo1LPcexMHaX94onETg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=EaKhh8VE288m0eWH7LRIaKcgC6cBcPCt3so3uponeLN33D/7uD4Tuy8eGpS/BtkJ5aFn8mCf5aq1q/tNkuLpneztQKDwVoBAYCMJn0IW1vi5ErFVLl847hjQKyTXXB3XgX7aMRW74hwbZqZjkZvPAoo8bmPoiIXdTDsjcOqlbPQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EBZTLNua; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="EBZTLNua" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A349DC116D0; Fri, 20 Feb 2026 06:34:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771569245; bh=Ial17sfZgdVRiZ5JFwlMSLgTFo1LPcexMHaX94onETg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EBZTLNuay2yyKESIcWpEoKJGo4zBffSI2G6ymTPRJKLu8EuK6qk9cn+K+b8PyMmKp plAp5fIjthS+U/Ei/t32XPcpzz6MbCPJuTVZjCOgCCqS9kwQrGvma9WOTpLDVFhZUf Xr1/SToJ9JyGZCP1mOfOjglWaUbH/cM5KfDRuGhs= Date: Fri, 20 Feb 2026 07:34:02 +0100 From: Greg Kroah-Hartman To: Danilo Krummrich Cc: Tariq Toukan , "Rafael J. Wysocki" , Saeed Mahameed , Leon Romanovsky , Mark Bloch , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-rdma@vger.kernel.org, Gal Pressman , Moshe Shemesh , Amir Tzin , Leon Romanovsky Subject: Re: [PATCH V2] driver core: auxiliary bus: Fix sysfs creation on bind Message-ID: <2026022040-casualty-dexterity-543c@gregkh> References: <20260219210435.1769394-1-tariqt@nvidia.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Feb 20, 2026 at 12:59:45AM +0100, Danilo Krummrich wrote: > On Thu Feb 19, 2026 at 10:04 PM CET, Tariq Toukan wrote: > > +/** > > + * auxiliary_device_sysfs_irq_dir_init - initialize the IRQ sysfs directory > > + * @auxdev: auxiliary bus device to initialize the sysfs directory. > > + * > > + * This function should be called by drivers to initialize the IRQ directory > > + * before adding any IRQ sysfs entries. The driver is responsible for ensuring > > + * this function is called only once and for handling any concurrency control > > + * if needed. > > + * > > + * Drivers must call auxiliary_device_sysfs_irq_dir_destroy() to clean up when > > + * done. > > + * > > + * Return: zero on success or an error code on failure. > > + */ > > +int auxiliary_device_sysfs_irq_dir_init(struct auxiliary_device *auxdev) > > { > > - int ret = 0; > > - > > - guard(mutex)(&auxdev->sysfs.lock); > > - if (auxdev->sysfs.irq_dir_exists) > > - return 0; > > + int ret; > > > > - ret = devm_device_add_group(&auxdev->dev, &auxiliary_irqs_group); > > + ret = sysfs_create_group(&auxdev->dev.kobj, &auxiliary_irqs_group); > > if (ret) > > return ret; > > > > - auxdev->sysfs.irq_dir_exists = true; > > xa_init(&auxdev->sysfs.irqs); > > return 0; > > } > > +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_dir_init); > > + > > +/** > > + * auxiliary_device_sysfs_irq_dir_destroy - destroy the IRQ sysfs directory > > + * @auxdev: auxiliary bus device to destroy the sysfs directory. > > + * > > + * This function should be called by drivers to clean up the IRQ directory > > + * after all IRQ sysfs entries have been removed. The driver is responsible > > + * for ensuring all IRQs are removed before calling this function. > > + */ > > +void auxiliary_device_sysfs_irq_dir_destroy(struct auxiliary_device *auxdev) > > +{ > > + xa_destroy(&auxdev->sysfs.irqs); > > + sysfs_remove_group(&auxdev->dev.kobj, &auxiliary_irqs_group); > > +} > > +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_dir_destroy); > > > > /** > > * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ > > @@ -45,7 +70,8 @@ static int auxiliary_irq_dir_prepare(struct auxiliary_device *auxdev) > > * @irq: The associated interrupt number. > > * > > * This function should be called after auxiliary device have successfully > > - * received the irq. > > + * received the irq. The driver must call auxiliary_device_sysfs_irq_dir_init() > > + * before calling this function for the first time. > > I'm not convinced by this approach. This adds two new sources of bugs for > drivers. > > 1. Drivers can now forget to call auxiliary_device_sysfs_irq_dir_init() > *before* auxiliary_device_sysfs_irq_add(). > > 2. Drivers can forget to call auxiliary_device_sysfs_irq_dir_destroy(). > > Instead, I suggest to keep the current approach and just replace > devm_device_add_group() with devm_auxiliary_device_add_group(), which in its > devres callback additionally clears auxdev->sysfs.irq_dir_exists. > > In terms of the auxdev->sysfs.lock, I think this can still be removed, as it > wasn't needed in the first place. > > auxiliary_device_sysfs_irq_add() must only be called from a scope where the > auxiliary device is guaranteed to be bound, so there can't be a concurrent > unbind. > > There may only be multiple concurrent calls to auxiliary_device_sysfs_irq_add() > itself, and in this case irq_dir_exists can just be an atomic. > > Yes, we're still stuck with an atomic for irq_dir_exists, but the driver API > remains much simpler and less error prone. I agree, your recommendations make sense. And I still hate this irq addition to auxdevices :( thanks, greg k-h