Re: [PATCH 4/7] x86/pci: use pcie_cap to simplify code
On 2013/9/4 10:59, Bjorn Helgaas wrote:
> On Tue, Sep 03, 2013 at 03:35:12PM +0800, Yijing Wang wrote:
>> PCI core saves PCIe Cap offset in pcie_cap,
>> use pcie_cap to simplify code.
>>
>> Signed-off-by: Yijing Wang
>> ---
>> arch/x86/pci/fixup.c |2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
>> index f5809fa..ee8330d 100644
>> --- a/arch/x86/pci/fixup.c
>> +++ b/arch/x86/pci/fixup.c
>> @@ -288,7 +288,7 @@ static void pcie_rootport_aspm_quirk(struct pci_dev
>> *pdev)
>> */
>> list_for_each_entry(dev, &pbus->devices, bus_list) {
>> /* There are 0 to 8 devices attached to this bus */
>> -cap_base = pci_find_capability(dev, PCI_CAP_ID_EXP);
>> +cap_base = dev->pcie_cap;
>> quirk_aspm_offset[GET_INDEX(pdev->device, dev->devfn)]
>> = cap_base + 0x10;
>
> This should use PCI_EXP_LNKCTL instead of "0x10".
>
>> }
>> pbus->ops = &quirk_pcie_aspm_ops;
Hi Bjorn,
Thanks for your review and comments!
>
> This quirk replaces the config accessors with ones that silently ignore
> writes to ASPM control bits. That really warrants at least a dev_info()
> note here, and we should be using pci_bus_set_ops().
Good idea, I will update it, thanks!
>
> Even that is a little bit dubious because I don't think this is really
> safe -- what happens if this quirk replaces the ops, then somebody
> else replaces the ops again? aer_inject.c at least keeps track of
> the old ops and seems to fall back to them, but it seems fragile to
> depend on every caller of pci_bus_set_ops() to do the right thing
> there.
>
> But this is beyond the scope of your patch, so if you just
> add a dev_info() note and use pci_bus_set_ops(), that should be
> enough for now.
>
>
--
Thanks!
Yijing
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Re: [PATCH 4/7] x86/pci: use pcie_cap to simplify code
On Tue, Sep 03, 2013 at 03:35:12PM +0800, Yijing Wang wrote:
> PCI core saves PCIe Cap offset in pcie_cap,
> use pcie_cap to simplify code.
>
> Signed-off-by: Yijing Wang
> ---
> arch/x86/pci/fixup.c |2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index f5809fa..ee8330d 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -288,7 +288,7 @@ static void pcie_rootport_aspm_quirk(struct pci_dev *pdev)
>*/
> list_for_each_entry(dev, &pbus->devices, bus_list) {
> /* There are 0 to 8 devices attached to this bus */
> - cap_base = pci_find_capability(dev, PCI_CAP_ID_EXP);
> + cap_base = dev->pcie_cap;
> quirk_aspm_offset[GET_INDEX(pdev->device, dev->devfn)]
> = cap_base + 0x10;
This should use PCI_EXP_LNKCTL instead of "0x10".
> }
> pbus->ops = &quirk_pcie_aspm_ops;
This quirk replaces the config accessors with ones that silently ignore
writes to ASPM control bits. That really warrants at least a dev_info()
note here, and we should be using pci_bus_set_ops().
Even that is a little bit dubious because I don't think this is really
safe -- what happens if this quirk replaces the ops, then somebody
else replaces the ops again? aer_inject.c at least keeps track of
the old ops and seems to fall back to them, but it seems fragile to
depend on every caller of pci_bus_set_ops() to do the right thing
there.
But this is beyond the scope of your patch, so if you just
add a dev_info() note and use pci_bus_set_ops(), that should be
enough for now.
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[PATCH 4/7] x86/pci: use pcie_cap to simplify code
PCI core saves PCIe Cap offset in pcie_cap,
use pcie_cap to simplify code.
Signed-off-by: Yijing Wang
---
arch/x86/pci/fixup.c |2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index f5809fa..ee8330d 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -288,7 +288,7 @@ static void pcie_rootport_aspm_quirk(struct pci_dev *pdev)
*/
list_for_each_entry(dev, &pbus->devices, bus_list) {
/* There are 0 to 8 devices attached to this bus */
- cap_base = pci_find_capability(dev, PCI_CAP_ID_EXP);
+ cap_base = dev->pcie_cap;
quirk_aspm_offset[GET_INDEX(pdev->device, dev->devfn)]
= cap_base + 0x10;
}
pbus->ops = &quirk_pcie_aspm_ops;
--
1.7.1
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