libata: make it clear that sata_inic162x is experimental

sata_inic162x never reached a state where it's reliable enough for
production use and data corruption is a relatively common occurrence.
Make the driver generate warning about the issues and mark the Kconfig
option as experimental.

If the situation doesn't improve, we'd be better off making it depend
on CONFIG_BROKEN.  Let's wait for several cycles and see if the kernel
message draws any attention.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Martin Braure de Calignon <braurede@free.fr>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: risc4all@yahoo.com

drivers/ata/Kconfig

@@ -107,7 +107,7 @@ config SATA_FSL
 	  If unsure, say N.
 
 config SATA_INIC162X
-	tristate "Initio 162x SATA support"
+	tristate "Initio 162x SATA support (Very Experimental)"
 	depends on PCI
 	help
 	  This option enables support for Initio 162x Serial ATA.

drivers/ata/sata_inic162x.c

@@ -6,6 +6,18 @@
  *
  * This file is released under GPL v2.
  *
+ * **** WARNING ****
+ *
+ * This driver never worked properly and unfortunately data corruption is
+ * relatively common.  There isn't anyone working on the driver and there's
+ * no support from the vendor.  Do not use this driver in any production
+ * environment.
+ *
+ * http://thread.gmane.org/gmane.linux.debian.devel.bugs.rc/378525/focus=54491
+ * https://bugzilla.kernel.org/show_bug.cgi?id=60565
+ *
+ * *****************
+ *
  * This controller is eccentric and easily locks up if something isn't
  * right.  Documentation is available at initio's website but it only
  * documents registers (not programming model).
@@ -807,6 +819,8 @@ static int inic_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	ata_print_version_once(&pdev->dev, DRV_VERSION);
 
+	dev_alert(&pdev->dev, "inic162x support is broken with common data corruption issues and will be disabled by default, contact linux-ide@vger.kernel.org if in production use\n");
+
 	/* alloc host */
 	host = ata_host_alloc_pinfo(&pdev->dev, ppi, NR_PORTS);
 	hpriv = devm_kzalloc(&pdev->dev, sizeof(*hpriv), GFP_KERNEL);