1 files changed, 37 insertions, 12 deletions

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index e33b68be0391..61345a18a6d1 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -209,6 +209,25 @@ static int find_valid_pos0(struct pcie_port *pp, int msgvec, int pos, int *pos0)
         return 0;
 }
 
+static void clear_irq_range(struct pcie_port *pp, unsigned int irq_base,
+                            unsigned int nvec, unsigned int pos)
+{
+        unsigned int i, res, bit, val;
+
+        i = 0;
+        while (i < nvec) {
+                irq_set_msi_desc_off(irq_base, i, NULL);
+                clear_bit(pos + i, pp->msi_irq_in_use);
+                /* Disable corresponding interrupt on MSI interrupt controller */
+                res = ((pos + i) / 32) * 12;
+                bit = (pos + i) % 32;
+                dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
+                val &= ~(1 << bit);
+                dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+                ++i;
+        }
+}
+
 static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
 {
         int res, bit, irq, pos0, pos1, i;
@@ -242,11 +261,20 @@ static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
         if (!irq)
                 goto no_valid_irq;
 
+        /*
+         * irq_create_mapping (called from dw_pcie_host_init) pre-allocates
+         * descs so there is no need to allocate descs here. We can therefore
+         * assume that if irq_find_mapping above returns non-zero, then the
+         * descs are also successfully allocated.
+         */
+
         i = 0;
         while (i < no_irqs) {
+                if (irq_set_msi_desc_off(irq, i, desc) != 0) {
+                        clear_irq_range(pp, irq, i, pos0);
+                        goto no_valid_irq;
+                }
                 set_bit(pos0 + i, pp->msi_irq_in_use);
-                irq_alloc_descs((irq + i), (irq + i), 1, 0);
-                irq_set_msi_desc(irq + i, desc);
                 /*Enable corresponding interrupt in MSI interrupt controller */
                 res = ((pos0 + i) / 32) * 12;
                 bit = (pos0 + i) % 32;
@@ -266,7 +294,7 @@ no_valid_irq:
 
 static void clear_irq(unsigned int irq)
 {
-        int res, bit, val, pos;
+        unsigned int pos, nvec;
         struct irq_desc *desc;
         struct msi_desc *msi;
         struct pcie_port *pp;
@@ -281,18 +309,15 @@ static void clear_irq(unsigned int irq)
                 return;
         }
 
+        /* undo what was done in assign_irq */
         pos = data->hwirq;
+        nvec = 1 << msi->msi_attrib.multiple;
 
-        irq_free_desc(irq);
-
-        clear_bit(pos, pp->msi_irq_in_use);
+        clear_irq_range(pp, irq, nvec, pos);
 
-        /* Disable corresponding interrupt on MSI interrupt controller */
-        res = (pos / 32) * 12;
-        bit = pos % 32;
-        dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
-        val &= ~(1 << bit);
-        dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+        /* all irqs cleared; reset attributes */
+        msi->irq = 0;
+        msi->msi_attrib.multiple = 0;
 }
 
 static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,