From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [119.145.14.64]) (using TLSv1 with cipher DES-CBC3-SHA (168/168 bits)) (Client CN "myname.my.domain", Issuer "www.mirapoint.com" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 72B202C00C8 for ; Fri, 11 Oct 2013 17:35:41 +1100 (EST) Message-ID: <52579BD6.40802@huawei.com> Date: Fri, 11 Oct 2013 14:33:58 +0800 From: Yijing Wang MIME-Version: 1.0 To: Gavin Shan Subject: Re: [PATCH v2 3/6] powerpc/pci: use pci_is_pcie() to simplify code References: <1378367730-25996-1-git-send-email-wangyijing@huawei.com> <1378367730-25996-3-git-send-email-wangyijing@huawei.com> <20130906203035.GA27940@google.com> <1381470596.5630.61.camel@pasglop> <20131011061654.GA561@shangw.(null)> In-Reply-To: <20131011061654.GA561@shangw.(null)> Content-Type: text/plain; charset="ISO-8859-1" Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, "James E.J. Bottomley" , Paul Mackerras , Hanjun Guo , Bjorn Helgaas , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 2013/10/11 14:16, Gavin Shan wrote: > On Fri, Oct 11, 2013 at 04:49:56PM +1100, Benjamin Herrenschmidt wrote: >> On Fri, 2013-09-06 at 14:30 -0600, Bjorn Helgaas wrote: >>> On Thu, Sep 05, 2013 at 03:55:27PM +0800, Yijing Wang wrote: >>>> Use pci_is_pcie() to simplify code. >>>> >>>> Acked-by: Kumar Gala >>>> Reviewed-by: Gavin Shan >>>> Signed-off-by: Yijing Wang >>>> Cc: Gavin Shan >>>> Cc: Benjamin Herrenschmidt >>>> Cc: Paul Mackerras >>>> Cc: linuxppc-dev@lists.ozlabs.org >>>> Cc: linux-kernel@vger.kernel.org >>>> --- >>>> arch/powerpc/kernel/eeh.c | 3 +-- >>>> arch/powerpc/sysdev/fsl_pci.c | 2 +- >>>> 2 files changed, 2 insertions(+), 3 deletions(-) >>> >>> Ben, Paul, this has no dependencies on anything new to PCI or any >>> other patches in this series, so you can take it through the POWERPC >>> tree. If you don't want to do that, let me know and I can take it. >>> >>> If you want it: >>> >>> Acked-by: Bjorn Helgaas >> >> It's also quite broken :-) >> >> See below: >> >>>> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c >>>> index 55593ee..6ebbe54 100644 >>>> --- a/arch/powerpc/kernel/eeh.c >>>> +++ b/arch/powerpc/kernel/eeh.c >>>> @@ -189,8 +189,7 @@ static size_t eeh_gather_pci_data(struct eeh_dev *edev, char * buf, size_t len) >>>> } >>>> >>>> /* If PCI-E capable, dump PCI-E cap 10, and the AER */ >>>> - cap = pci_find_capability(dev, PCI_CAP_ID_EXP); >>>> - if (cap) { >>>> + if (pci_is_pcie(dev)) { >>>> n += scnprintf(buf+n, len-n, "pci-e cap10:\n"); >>>> printk(KERN_WARNING >>>> "EEH: PCI-E capabilities and status follow:\n"); >> >> So we remove reading of "cap", but slightly further down the code does: >> >> for (i=0; i<=8; i++) { >> eeh_ops->read_config(dn, cap+4*i, 4, &cfg); >> n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); >> printk(KERN_WARNING "EEH: PCI-E %02x: %08x\n", i, cfg); >> } >> >> Which actually *uses* the value of "cap" ... oops :-) >> > > It's my fault and I should have looked into the changes more closely. > How about changing it like this: > > cap = pci_is_pcie(dev) ? pci_pcie_cap(dev) : > pci_find_capability(dev, PCI_CAP_ID_EXP); > if (cap) { > ... > } > > It would save some PCI-CFG access cycles for most cases :-) Hi Gavin, it's not your fault, it's my fault. :) Because pci_pcie_cap(dev) == dev->pcie_cap == pci_find_capability(dev, PCI_CAP_ID_EXP); so I think it's ok to use dev->pcie_cap instead of stale "cap". I have updated this patch. Thanks for your review and comments! Thanks! Yijing. > >>>> diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c >>>> index 46ac1dd..5402a1d 100644 >>>> --- a/arch/powerpc/sysdev/fsl_pci.c >>>> +++ b/arch/powerpc/sysdev/fsl_pci.c >>>> @@ -41,7 +41,7 @@ static void quirk_fsl_pcie_header(struct pci_dev *dev) >>>> u8 hdr_type; >>>> >>>> /* if we aren't a PCIe don't bother */ >>>> - if (!pci_find_capability(dev, PCI_CAP_ID_EXP)) >>>> + if (!pci_is_pcie(dev)) >>>> return; >>>> >>>> /* if we aren't in host mode don't bother */ > > Thanks, > Gavin > > > . > -- Thanks! Yijing