s390: pci: Check return value of alloc_irq_desc() proper

alloc_irq_desc() returns an integer and as documented either a valid
irq number or a negative error code. Checking for NO_IRQ is definitely
not the proper error handling.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Link: http://lkml.kernel.org/r/20140507154339.409085048@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 1df1d29ac81d3710caafad1f7ce0094f530d721d..2c0076d462b84e692dc482e1d092e101b9bad7f4 100644 (file)
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -401,11 +401,11 @@ static void zpci_irq_handler(struct airq_struct *airq)
 int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
        struct zpci_dev *zdev = get_zdev(pdev);
-       unsigned int hwirq, irq, msi_vecs;
+       unsigned int hwirq, msi_vecs;
        unsigned long aisb;
        struct msi_desc *msi;
        struct msi_msg msg;
-       int rc;
+       int rc, irq;
 
        if (type == PCI_CAP_ID_MSI && nvec > 1)
                return 1;
@@ -433,7 +433,7 @@ int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
        list_for_each_entry(msi, &pdev->msi_list, list) {
                rc = -EIO;
                irq = irq_alloc_desc(0);        /* Alloc irq on node 0 */
-               if (irq == NO_IRQ)
+               if (irq < 0)
                        goto out_msi;
                rc = irq_set_msi_desc(irq, msi);
                if (rc)