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-rw-r--r--Documentation/powerpc/eeh-pci-error-recovery.txt15
1 files changed, 8 insertions, 7 deletions
diff --git a/Documentation/powerpc/eeh-pci-error-recovery.txt b/Documentation/powerpc/eeh-pci-error-recovery.txt
index 67a11a36270c..3764dd4b12cb 100644
--- a/Documentation/powerpc/eeh-pci-error-recovery.txt
+++ b/Documentation/powerpc/eeh-pci-error-recovery.txt
@@ -121,7 +121,7 @@ accomplished.
121 121
122EEH must be enabled in the PHB's very early during the boot process, 122EEH must be enabled in the PHB's very early during the boot process,
123and if a PCI slot is hot-plugged. The former is performed by 123and if a PCI slot is hot-plugged. The former is performed by
124eeh_init() in arch/ppc64/kernel/eeh.c, and the later by 124eeh_init() in arch/powerpc/platforms/pseries/eeh.c, and the later by
125drivers/pci/hotplug/pSeries_pci.c calling in to the eeh.c code. 125drivers/pci/hotplug/pSeries_pci.c calling in to the eeh.c code.
126EEH must be enabled before a PCI scan of the device can proceed. 126EEH must be enabled before a PCI scan of the device can proceed.
127Current Power5 hardware will not work unless EEH is enabled; 127Current Power5 hardware will not work unless EEH is enabled;
@@ -133,7 +133,7 @@ error. Given an arbitrary address, the routine
133pci_get_device_by_addr() will find the pci device associated 133pci_get_device_by_addr() will find the pci device associated
134with that address (if any). 134with that address (if any).
135 135
136The default include/asm-ppc64/io.h macros readb(), inb(), insb(), 136The default include/asm-powerpc/io.h macros readb(), inb(), insb(),
137etc. include a check to see if the i/o read returned all-0xff's. 137etc. include a check to see if the i/o read returned all-0xff's.
138If so, these make a call to eeh_dn_check_failure(), which in turn 138If so, these make a call to eeh_dn_check_failure(), which in turn
139asks the firmware if the all-ff's value is the sign of a true EEH 139asks the firmware if the all-ff's value is the sign of a true EEH
@@ -143,11 +143,12 @@ seen in /proc/ppc64/eeh (subject to change). Normally, almost
143all of these occur during boot, when the PCI bus is scanned, where 143all of these occur during boot, when the PCI bus is scanned, where
144a large number of 0xff reads are part of the bus scan procedure. 144a large number of 0xff reads are part of the bus scan procedure.
145 145
146If a frozen slot is detected, code in arch/ppc64/kernel/eeh.c will 146If a frozen slot is detected, code in
147print a stack trace to syslog (/var/log/messages). This stack trace 147arch/powerpc/platforms/pseries/eeh.c will print a stack trace to
148has proven to be very useful to device-driver authors for finding 148syslog (/var/log/messages). This stack trace has proven to be very
149out at what point the EEH error was detected, as the error itself 149useful to device-driver authors for finding out at what point the EEH
150usually occurs slightly beforehand. 150error was detected, as the error itself usually occurs slightly
151beforehand.
151 152
152Next, it uses the Linux kernel notifier chain/work queue mechanism to 153Next, it uses the Linux kernel notifier chain/work queue mechanism to
153allow any interested parties to find out about the failure. Device 154allow any interested parties to find out about the failure. Device