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Date: Sat, 4 May 2024 17:48:06 +0200
From: Nam Cao <namcao@linutronix.de>
To: Lukas Wunner <lukas@wunner.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>, Yinghai Lu <yinghai@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rajesh Shah <rajesh.shah@intel.com>, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 2/4] PCI: pciehp: bail out if pci_hp_add_bridge() fails
Message-ID: <20240504154806.zpZEo__F@linutronix.de>
References: <cover.1714762038.git.namcao@linutronix.de>
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 <ZjX3t1NerOlGBhzw@wunner.de>
 <20240504093529.p8pbGxuK@linutronix.de>
 <ZjYFOrGlluGW_GzV@wunner.de>
 <20240504105630.DPSzrgHe@linutronix.de>
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In-Reply-To: <ZjZOCj4Cxizsj3iY@wunner.de>

On Sat, May 04, 2024 at 05:02:34PM +0200, Lukas Wunner wrote:
> On Sat, May 04, 2024 at 12:56:30PM +0200, Nam Cao wrote:
> > On Sat, May 04, 2024 at 11:51:54AM +0200, Lukas Wunner wrote:
> > > Could you reproduce with pciehp instead of shpchp please?
> > 
> > Same thing for pciehp below. I think the problem is because without 
> > pci_stop_and_remove_bus_device(), no one cleans up the device added in
> > pci_scan_slot(). When another device get hot-added, pci_get_slot() wrongly
> > thinks another device is already there, so the hot-plug fails.
> 
> pciehp powers down the slot because you're returning a negative errno
> from pciehp_configure_device().  Please return 0 instead if
> pci_hp_add_bridge() fails.

Thanks for the suggestion. This is applicable to shpchp as well.

Best regards,
Nam