sdio: make the IRQ thread more resilient in the presence of bad states

Currently we print a message about some bad states wrt function IRQ
handlers but return 0 from process_sdio_pending_irqs() nevertheless.
This can lead to an infinite loop as nothing might have cleared the
condition for the pending card interrupt from the host controller by
the time host->ops->enable_sdio_irq(host, 1) is called.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index e7865059e126..3bd3021f5e80 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -45,16 +45,22 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
                                 printk(KERN_WARNING "%s: pending IRQ for "
                                         "non-existant function\n",
                                         mmc_card_id(card));
+                                ret = -EINVAL;
                         } else if (func->irq_handler) {
                                 func->irq_handler(func);
                                 count++;
-                        } else
+                        } else {
                                 printk(KERN_WARNING "%s: pending IRQ with no handler\n",
                                        sdio_func_id(func));
+                                ret = -EINVAL;
+                        }
                 }
         }
 
-        return count;
+        if (count)
+                return count;
+
+        return ret;
 }
 
 static int sdio_irq_thread(void *_host)