ahci: Add check for device presence (PCIe hot unplug) in ahci_stop_engine()

Exit directly with ENODEV, if the AHCI controller is not available
anymore. Otherwise a delay of 500ms for each port is added to the remove
function while trying to issue a command on the non-existent controller.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index a0de7a38430c954b31c7b4e6e01a790ee98e85c2..7adcf3caabd00abbb08ef76c0e4e604f0ba8c97c 100644 (file)
--- 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);