On 12/02/2008 12:23 PM, Stephen Hemminger wrote:
This patch does more error checking in the Advanced Error Reporting code.
Since AER needs to access PCI registers > 255, it won't work without MMCONFIG
and other quirks may stop it as well. The code must check this by looking
at return values from pci_read/write_config_XXX calls.
I don't have any hardware that uses AER routines but discovered this
in earlier versions of the sky2 driver that tried to use
pci AER routines. Ended up just giving up and using other ways to access PCI
config space on sky2 since there were too many platform glitches.
When experimenting with sky2 driver, was pci_find_ext_capability()
returning non-zero although further ext-space accesses were failing?
Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
--- a/drivers/pci/pcie/aer/aerdrv_core.c 2008-12-02 07:56:08.000000000 -0800
+++ b/drivers/pci/pcie/aer/aerdrv_core.c 2008-12-02 09:07:32.000000000 -0800
@@ -31,80 +31,92 @@ module_param(forceload, bool, 0);
int pci_enable_pcie_error_reporting(struct pci_dev *dev)
{
u16 reg16 = 0;
- int pos;
+ int pos, err;
+ u32 status;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
if (!pos)
return -EIO;
+ err = pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
+ if (err)
+ return err;
+
For legacy-conf-space, most kernel code assumes success without
checking. For ext-conf-space, wouldn't it be convenient to be able to
make the same assumption when pci_find_ext_capability() returns a valid
offset?
The patch looks good to me, but I am just asking whether there is a
known case where pcie_find_ext_capability() returns a valid offset,
although that offset might turn out unusable (it might be worth
investigating pci_find_ext_capability() then).
Loic
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