Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <f34130034637278c9999cf6d430be558cb0c2318.camel@linux.ibm.com>
Subject: Re: [PATCH RESEND v5 1/4] PCI: Clean up pci_scan_slot()
From:   Niklas Schnelle <schnelle@linux.ibm.com>
To:     Bjorn Helgaas <bhelgaas@google.com>,
        Jan Kiszka <jan.kiszka@siemens.com>,
        Matthew Rosato <mjrosato@linux.ibm.com>,
        Pierre Morel <pmorel@linux.ibm.com>
Cc:     linux-kernel@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        linux-s390@vger.kernel.org, linux-pci@vger.kernel.org
Date:   Thu, 12 May 2022 16:56:42 +0200
In-Reply-To: <20220505083839.1315705-2-schnelle@linux.ibm.com>
References: <20220505083839.1315705-1-schnelle@linux.ibm.com>
         <20220505083839.1315705-2-schnelle@linux.ibm.com>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Thu, 2022-05-05 at 10:38 +0200, Niklas Schnelle wrote:
> While determining the next PCI function is factored out of
> pci_scan_slot() into next_fn() the former still handles the first
> function as a special case. This duplicates the code from the scan loop.
> 
> Furthermore the non ARI branch of next_fn() is generally hard to
> understand and especially the check for multifunction devices is hidden
> in the handling of NULL devices for non-contiguous multifunction. It
> also signals that no further functions need to be scanned by returning
> 0 via wraparound and this is a valid function number.
> 
> Improve upon this by transforming the conditions in next_fn() to be
> easier to understand.
> 
> By changing next_fn() to return -ENODEV instead of 0 when there is no
> next function we can then handle the initial function inside the loop
> and deduplicate the shared handling. This also makes it more explicit
> that only function 0 must exist.
> 
> No functional change is intended.
> 
> Cc: Jan Kiszka <jan.kiszka@siemens.com>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---

Friendly ping :-)