[51/75] sparc64: Fix MSIQ HV call ordering in pci_sun4v_msiq_build_irq().

[Greg KH]

3.1-stable review patch.  If anyone has any objections, please let me know.

------------------


From: "David S. Miller" <davem@xxxxxxxxxxxxx>

[ Upstream commit 7cc8583372a21d98a23b703ad96cab03180b5030 ]

This silently was working for many years and stopped working on
Niagara-T3 machines.

We need to set the MSIQ to VALID before we can set it's state to IDLE.

On Niagara-T3, setting the state to IDLE first was causing HV_EINVAL
errors.  The hypervisor documentation says, rather ambiguously, that
the MSIQ must be "initialized" before one can set the state.

I previously understood this to mean merely that a successful setconf()
operation has been performed on the MSIQ, which we have done at this
point.  But it seems to also mean that it has been set VALID too.

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 arch/sparc/kernel/pci_sun4v.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -848,10 +848,10 @@ static int pci_sun4v_msiq_build_irq(stru
 	if (!irq)
 		return -ENOMEM;
 
-	if (pci_sun4v_msiq_setstate(pbm->devhandle, msiqid, HV_MSIQSTATE_IDLE))
-		return -EINVAL;
 	if (pci_sun4v_msiq_setvalid(pbm->devhandle, msiqid, HV_MSIQ_VALID))
 		return -EINVAL;
+	if (pci_sun4v_msiq_setstate(pbm->devhandle, msiqid, HV_MSIQSTATE_IDLE))
+		return -EINVAL;
 
 	return irq;
 }


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