From: Bryan Boatright Date: Thu, 7 Feb 2008 08:14:58 +0000 (-0800) Subject: drivers/edac: pci: broken parity regression X-Git-Tag: v2.6.25-rc1~415 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b09ff9d787911b0b46a4d286e68f1f84e8b0b94;p=linux-2.6 drivers/edac: pci: broken parity regression Using the EDAC code in kernel.org kernel version 2.6.23.8 I am seeing the following problem: In the kernel there is a pci device attribute located in sysfs that is checked by the EDAC PCI scanning code. If that attribute is set, PCI parity/error scannining is skipped for that device. The attribute is: broken_parity_status as is located in /sys/devices/pci/0000:XX:YY.Z directorys for PCI devices. I don't think this check was actually implemented. I have a misbehaved card that reports a parity error every 1000 ms: Nov 25 07:28:43 beta kernel: EDAC PCI: Master Data Parity Error on 0000:05:01.0 Nov 25 07:28:44 beta kernel: EDAC PCI: Master Data Parity Error on 0000:05:01.0 Nov 25 07:28:45 beta kernel: EDAC PCI: Master Data Parity Error on 0000:05:01.0 Setting that card's broken_parity_status bit did not mask the error: echo "1" > /sys/bus/pci/devices/0000:05:01.0/broken_parity_status I looked through the EDAC code and did not readily see any reference to broken_parity_status at all (which makes sense based on the behavior I am seeing). I applied the following patch as a proof-of-concept and now EDAC's PCI parity error reporting behaves as documented: bryan Good regression find, bryan. It used to work. sigh. I added more logic to your patch, for more coverage of the error. Doug T Signed-off-by: Bryan Boatright Signed-off-by: Doug Thompson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/edac/edac_pci_sysfs.c b/drivers/edac/edac_pci_sysfs.c index 5b075da991..71c3195d37 100644 --- a/drivers/edac/edac_pci_sysfs.c +++ b/drivers/edac/edac_pci_sysfs.c @@ -558,8 +558,10 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) debugf4("PCI STATUS= 0x%04x %s\n", status, dev->dev.bus_id); - /* check the status reg for errors */ - if (status) { + /* check the status reg for errors on boards NOT marked as broken + * if broken, we cannot trust any of the status bits + */ + if (status && !dev->broken_parity_status) { if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) { edac_printk(KERN_CRIT, EDAC_PCI, "Signaled System Error on %s\n", @@ -593,8 +595,10 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) debugf4("PCI SEC_STATUS= 0x%04x %s\n", status, dev->dev.bus_id); - /* check the secondary status reg for errors */ - if (status) { + /* check the secondary status reg for errors, + * on NOT broken boards + */ + if (status && !dev->broken_parity_status) { if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) { edac_printk(KERN_CRIT, EDAC_PCI, "Bridge " "Signaled System Error on %s\n",