From d523cc379da57f1c39f5db9c47bdaa94f74727ff Mon Sep 17 00:00:00 2001
From: Michael Ellerman <michael@ellerman.id.au>
Date: Tue, 17 Feb 2009 00:18:49 +0000
Subject: [PATCH] powerpc/pseries: Return req#msi(-x) if request is larger

If a driver asks for more MSIs than the devices "req#msi(-x)" property,
we currently return -ENOSPC. This doesn't give the driver any chance to
make a new request with a number that might work.

So if "req#msi(-x)" is less than the request, return its value. To be
100% safe, make sure we return an error if req_msi == 0.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/platforms/pseries/msi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index 073b518338a3f6..081af6d7fa025a 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -154,7 +154,11 @@ static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
 
 	if (*req_msi < nvec) {
 		pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);
-		return -ENOSPC;
+
+		if (*req_msi == 0) /* Be paranoid */
+			return -ENOSPC;
+
+		return *req_msi;
 	}
 
 	return 0;
-- 
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