From: Jason Uhlenkott <[email protected]>
If ERRSTS indicates that there's no error then we don't need to bother
reading the other registers.
In addition to making the common case faster, this actually fixes a
small race where we don't see an error but we clear the error bits
anyway, potentially wiping away info on an error that happened in the
interim (or where a CE arrives between the first and second read of
ERRSTS, causing us to falsely claim "UE overwrote CE").
Signed-off-by: Jason Uhlenkott <[email protected]>
Signed-off-by: Douglas Thompson <[email protected]>
Cc: [email protected]
---
i82875p_edac.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- linux.orig/drivers/edac/i82875p_edac.c 2007-05-21 00:46:31.568356390 -0400
+++ linux/drivers/edac/i82875p_edac.c 2007-05-21 00:46:36.637650484 -0400
@@ -198,27 +198,28 @@
* overwritten by UE.
*/
pci_read_config_word(pdev, I82875P_ERRSTS, &info->errsts);
+
+ if (!(info->errsts & 0x0081))
+ return;
+
pci_read_config_dword(pdev, I82875P_EAP, &info->eap);
pci_read_config_byte(pdev, I82875P_DES, &info->des);
pci_read_config_byte(pdev, I82875P_DERRSYN, &info->derrsyn);
pci_read_config_word(pdev, I82875P_ERRSTS, &info->errsts2);
- pci_write_bits16(pdev, I82875P_ERRSTS, 0x0081, 0x0081);
-
/*
* If the error is the same then we can for both reads then
* the first set of reads is valid. If there is a change then
* there is a CE no info and the second set of reads is valid
* and should be UE info.
*/
- if (!(info->errsts2 & 0x0081))
- return;
-
if ((info->errsts ^ info->errsts2) & 0x0081) {
pci_read_config_dword(pdev, I82875P_EAP, &info->eap);
pci_read_config_byte(pdev, I82875P_DES, &info->des);
pci_read_config_byte(pdev, I82875P_DERRSYN, &info->derrsyn);
}
+
+ pci_write_bits16(pdev, I82875P_ERRSTS, 0x0081, 0x0081);
}
static int i82875p_process_error_info(struct mem_ctl_info *mci,
@@ -229,7 +230,7 @@
multi_chan = mci->csrows[0].nr_channels - 1;
- if (!(info->errsts2 & 0x0081))
+ if (!(info->errsts & 0x0081))
return 0;
if (!handle_errors)