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* [PATCH] Restore PERR/SERR bit settings during EEH device recovery
@ 2008-07-08  3:18 Mike Mason
  2008-07-08 13:38 ` Linas Vepstas
  0 siblings, 1 reply; 4+ messages in thread
From: Mike Mason @ 2008-07-08  3:18 UTC (permalink / raw)
  To: paulus, benh, linasvepstas, linuxppc-dev

The following patch restores the PERR and SERR bits in the PCI
command register during an EEH device recovery.
We have found at least one case (an Agilent test card) where the
PERR/SERR bits are set to 1 by firmware at boot time, but are
not restored to 1 during EEH recovery.  The patch fixes the
Agilent card problem.  It has been tested on several other 
EEH-enabled cards with no regressions.

Signed-off-by: Mike Mason <mmlnx@us.ibm.com>

--- linux-2.6.26-rc9/arch/powerpc/platforms/pseries/eeh.c	2008-07-07 16:06:57.000000000 -0700
+++ linux-2.6.26-rc9-new/arch/powerpc/platforms/pseries/eeh.c	2008-07-07 16:11:10.000000000 -0700
@@ -812,6 +812,7 @@
 static inline void __restore_bars (struct pci_dn *pdn)
 {
 	int i;
+	u32 cmd;
 
 	if (NULL==pdn->phb) return;
 	for (i=4; i<10; i++) {
@@ -832,6 +833,15 @@
 
 	/* max latency, min grant, interrupt pin and line */
 	rtas_write_config(pdn, 15*4, 4, pdn->config_space[15]);
+
+	/* Restore PERR & SERR bits, some devices require it,
+	   don't touch the other command bits */
+	rtas_read_config(pdn, PCI_COMMAND, 4, &cmd);
+	if (pdn->config_space[1] & PCI_COMMAND_PARITY)
+		cmd |= PCI_COMMAND_PARITY;
+	if (pdn->config_space[1] & PCI_COMMAND_SERR)
+		cmd |= PCI_COMMAND_SERR;
+	rtas_write_config(pdn, PCI_COMMAND, 4, cmd);
 }
 
 /**

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2008-07-08 16:04 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-07-08  3:18 [PATCH] Restore PERR/SERR bit settings during EEH device recovery Mike Mason
2008-07-08 13:38 ` Linas Vepstas
2008-07-08 15:56   ` Mike Mason
2008-07-08 16:04   ` Mike Mason

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