* [PATCH 1/1] pci-iov: Fix warnings when CONFIG_PCI_IOV is enabled
@ 2012-09-04 23:11 Jiang Wang
2012-09-11 23:35 ` Bjorn Helgaas
0 siblings, 1 reply; 3+ messages in thread
From: Jiang Wang @ 2012-09-04 23:11 UTC (permalink / raw)
To: Bjorn Helgaas, linux-pci, linux-kernel
Cc: clala, Francis.St.Amant, Jiang Wang, Jiang Wang
When CONFIG_PCI_IOV is enabled, the kernel will call sriov_init().
This function tries to allocate virtual resources even if the
virtual function of a PCI devive is not enabled by the BIOS.
This sometimes causes following warning messages during boot up:
pci 0000:02:00.0: BAR 9: can't allocate mem resource [0x000000-0x3fffff]
pci 0000:02:00.0: BAR 7: can't allocate mem resource [0x000000-0x03ffff]
Tested on three Mitac motherboards.
Signed-off-by: Jiang Wang <jwang@riverbed.com>
---
drivers/pci/iov.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 6554e1a..0ca8cb2 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -441,7 +441,8 @@ static int sriov_init(struct pci_dev *dev, int pos)
if (ctrl & PCI_SRIOV_CTRL_VFE) {
pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
ssleep(1);
- }
+ } else
+ return 0;
pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
if (!total)
--
1.7.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 1/1] pci-iov: Fix warnings when CONFIG_PCI_IOV is enabled
2012-09-04 23:11 [PATCH 1/1] pci-iov: Fix warnings when CONFIG_PCI_IOV is enabled Jiang Wang
@ 2012-09-11 23:35 ` Bjorn Helgaas
2012-09-12 1:13 ` Jiang Wang
0 siblings, 1 reply; 3+ messages in thread
From: Bjorn Helgaas @ 2012-09-11 23:35 UTC (permalink / raw)
To: Jiang Wang; +Cc: linux-pci, linux-kernel, clala, Francis.St.Amant, Jiang Wang
On Tue, Sep 4, 2012 at 5:11 PM, Jiang Wang <Jiang.Wang@riverbed.com> wrote:
> When CONFIG_PCI_IOV is enabled, the kernel will call sriov_init().
> This function tries to allocate virtual resources even if the
> virtual function of a PCI devive is not enabled by the BIOS.
>
> This sometimes causes following warning messages during boot up:
> pci 0000:02:00.0: BAR 9: can't allocate mem resource [0x000000-0x3fffff]
> pci 0000:02:00.0: BAR 7: can't allocate mem resource [0x000000-0x03ffff]
>
> Tested on three Mitac motherboards.
>
> Signed-off-by: Jiang Wang <jwang@riverbed.com>
> ---
> drivers/pci/iov.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index 6554e1a..0ca8cb2 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -441,7 +441,8 @@ static int sriov_init(struct pci_dev *dev, int pos)
> if (ctrl & PCI_SRIOV_CTRL_VFE) {
> pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
> ssleep(1);
> - }
> + } else
> + return 0;
But this would mean that Linux can't *ever* enable VFs unless the BIOS
enabled them, right? I don't think that's what we want -- there's
code in sriov_enable() to turn on VFE, assuming we have enough
resources for the VFs.
It's certainly possible that the BIOS didn't allocate large enough
apertures in the bridges leading to the SR-IOV device to accommodate
all the VFs, and Linux may not be smart enough to enlarge them. And
probably our warning messages in that case are not very enlightening.
Bjorn
> pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
> if (!total)
> --
> 1.7.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: [PATCH 1/1] pci-iov: Fix warnings when CONFIG_PCI_IOV is enabled
2012-09-11 23:35 ` Bjorn Helgaas
@ 2012-09-12 1:13 ` Jiang Wang
0 siblings, 0 replies; 3+ messages in thread
From: Jiang Wang @ 2012-09-12 1:13 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: linux-pci, linux-kernel, Chaitanya Lala, Francis St. Amant
-----Original Message-----
From: Bjorn Helgaas [mailto:bhelgaas@google.com]
Sent: Tuesday, September 11, 2012 4:35 PM
To: Jiang Wang
Cc: linux-pci@vger.kernel.org; linux-kernel@vger.kernel.org; Chaitanya Lala; Francis St. Amant; Jiang Wang
Subject: Re: [PATCH 1/1] pci-iov: Fix warnings when CONFIG_PCI_IOV is enabled
On Tue, Sep 4, 2012 at 5:11 PM, Jiang Wang <Jiang.Wang@riverbed.com> wrote:
> When CONFIG_PCI_IOV is enabled, the kernel will call sriov_init().
> This function tries to allocate virtual resources even if the virtual
> function of a PCI devive is not enabled by the BIOS.
>
> This sometimes causes following warning messages during boot up:
> pci 0000:02:00.0: BAR 9: can't allocate mem resource
> [0x000000-0x3fffff] pci 0000:02:00.0: BAR 7: can't allocate mem
> resource [0x000000-0x03ffff]
>
> Tested on three Mitac motherboards.
>
> Signed-off-by: Jiang Wang <jwang@riverbed.com>
> ---
> drivers/pci/iov.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index
> 6554e1a..0ca8cb2 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -441,7 +441,8 @@ static int sriov_init(struct pci_dev *dev, int pos)
> if (ctrl & PCI_SRIOV_CTRL_VFE) {
> pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
> ssleep(1);
> - }
> + } else
> + return 0;
But this would mean that Linux can't *ever* enable VFs unless the BIOS enabled them, right? I don't think that's what we want -- there's code in sriov_enable() to turn on VFE, assuming we have enough resources for the VFs.
--- I see. I didn't find the code in sriov_enable() before I send out the patch. Thanks for the info.
It's certainly possible that the BIOS didn't allocate large enough apertures in the bridges leading to the SR-IOV device to accommodate all the VFs, and Linux may not be smart enough to enlarge them. And probably our warning messages in that case are not very enlightening.
---- My purpose here is to remove those warnings. I also tried to disable CONFIG_PCI_IOV, but that causes another strange problem on one of machines. The LSI controller cannot get memory resources and 32 LSI controllers shown up even though only one actually exist.
I will drop this patch and do more debug to see what that problem is. Thanks.
Bjorn
> pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
> if (!total)
> --
> 1.7.1
>
Regards,
Jiang
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-09-04 23:11 [PATCH 1/1] pci-iov: Fix warnings when CONFIG_PCI_IOV is enabled Jiang Wang
2012-09-11 23:35 ` Bjorn Helgaas
2012-09-12 1:13 ` Jiang Wang
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