1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index a0de7a38430c..7adcf3caabd0 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -665,6 +665,16 @@ int ahci_stop_engine(struct ata_port *ap)
         if ((tmp & (PORT_CMD_START | PORT_CMD_LIST_ON)) == 0)
                 return 0;
 
+        /*
+         * Don't try to issue commands but return with ENODEV if the
+         * AHCI controller not available anymore (e.g. due to PCIe hot
+         * unplugging). Otherwise a 500ms delay for each port is added.
+         */
+        if (tmp == 0xffffffff) {
+                dev_err(ap->host->dev, "AHCI controller unavailable!\n");
+                return -ENODEV;
+        }
+
         /* setting HBA to idle */
         tmp &= ~PORT_CMD_START;
         writel(tmp, port_mmio + PORT_CMD);