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From: Bjorn Helgaas <bhelgaas@google.com>
To: Wei Yang <weiyang@linux.vnet.ibm.com>
Cc: linux-pci@vger.kernel.org
Subject: Re: [PATCH V2 4/4] PCI: consolidate return value check for pci_find_(ext_)capability
Date: Tue, 14 Jul 2015 17:00:21 -0500	[thread overview]
Message-ID: <20150714220021.GL24416@google.com> (raw)
In-Reply-To: <1435627004-6029-5-git-send-email-weiyang@linux.vnet.ibm.com>

On Tue, Jun 30, 2015 at 09:16:44AM +0800, Wei Yang wrote:
> The return value of the pci_find_(ext_)capability is the position of this
> Cap.  After previous two patches clean up, the position returned is an
> unsigned value. Only 0 indicates the Cap is not presented.
> 
> This patch consolidates the form of check from (pos <= 0)to (!pos).
> 
> Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>

Applied to pci/misc with changelog as below.

It seems pretty clear to me that pci_find_capability() returns either 0 or
a u8 value.  pci_find_ext_capability() does return an int.  It looks to me
like it can never be negative, but if you wanted it to be even more clear,
you could easily change just pci_find_next_ext_capability() to use a u16
for "pos".  That would be very simple and wouldn't change any interfaces.

commit d5fa86074987b1b5fcbfba8c9315e75ff7262f71
Author: Wei Yang <weiyang@linux.vnet.ibm.com>
Date:   Tue Jun 30 09:16:44 2015 +0800

    PCI: Simplify pci_find_(ext_)capability() return value checks
    
    The return value of the pci_find_(ext_)capability() is either zero or the
    position of a capability.  It is never negative.
    
    This patch consolidates the form of check from (pos <= 0) to (!pos).
    
    Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
    Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

  reply	other threads:[~2015-07-14 22:00 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-30  1:16 [PATCH V2 0/4] PCI: code clean up on pci configuration space Wei Yang
2015-06-30  1:16 ` [PATCH V2 1/4] PCI: move PCI_FIND_CAP_TTL to pci.h and use it in quirks Wei Yang
2015-07-14 21:57   ` Bjorn Helgaas
2015-06-30  1:16 ` [PATCH V2 2/4] PCI: use u8 to represent pci configuration space pos and cap Wei Yang
2015-06-30  1:16 ` [PATCH V2 3/4] PCI: use u16 to represent pci express extended capabilities " Wei Yang
2015-06-30  1:16 ` [PATCH V2 4/4] PCI: consolidate return value check for pci_find_(ext_)capability Wei Yang
2015-07-14 22:00   ` Bjorn Helgaas [this message]
2015-07-15  2:02     ` Wei Yang
2015-07-15  2:11       ` Bjorn Helgaas
2015-07-15  5:46         ` Wei Yang
2015-07-14 21:37 ` [PATCH V2 0/4] PCI: code clean up on pci configuration space Bjorn Helgaas
2015-07-15  2:08   ` Wei Yang

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