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Date:   Mon, 9 May 2022 06:01:39 +0200
From:   Lukas Wunner <lukas@wunner.de>
To:     Marek =?iso-8859-1?Q?Beh=FAn?= <kabel@kernel.org>
Cc:     Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Krzysztof Wilczy??ski <kw@linux.com>,
        Marc Zyngier <maz@kernel.org>, pali@kernel.org,
        linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Gregory CLEMENT <gregory.clement@bootlin.com>
Subject: Re: [PATCH 07/18] PCI: pciehp: Enable Command Completed Interrupt
 only if supported
Message-ID: <20220509040139.GB26780@wunner.de>
References: <20220220193346.23789-1-kabel@kernel.org>
 <20220220193346.23789-8-kabel@kernel.org>
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On Sun, Feb 20, 2022 at 08:33:35PM +0100, Marek Behún wrote:
> The No Command Completed Support bit in the Slot Capabilities register
> indicates whether Command Completed Interrupt Enable is unsupported.
> 
> Enable this interrupt only in the case it is supported.
[...]
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -817,7 +817,9 @@ static void pcie_enable_notification(struct controller *ctrl)
>  	else
>  		cmd |= PCI_EXP_SLTCTL_PDCE;
>  	if (!pciehp_poll_mode)
> -		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
> +		cmd |= PCI_EXP_SLTCTL_HPIE;
> +	if (!pciehp_poll_mode && !NO_CMD_CMPL(ctrl))
> +		cmd |= PCI_EXP_SLTCTL_CCIE;

Looks okay to me in principle, I'm just wondering why this change is
necessary, i.e. what issue are you seeing without it?

Thanks,

Lukas