1 files changed, 15 insertions, 8 deletions

diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index c49ad0e61b6f..f65b53785a8f 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -421,26 +421,33 @@ static struct ata_port_operations nv_generic_ops = {
         .hardreset              = ATA_OP_NULL,
 };
 
-/* OSDL bz3352 reports that nf2/3 controllers can't determine device
- * signature reliably.  Also, the following thread reports detection
- * failure on cold boot with the standard debouncing timing.
+/* nf2 is ripe with hardreset related problems.
+ *
+ * kernel bz#3352 reports nf2/3 controllers can't determine device
+ * signature reliably.  The following thread reports detection failure
+ * on cold boot with the standard debouncing timing.
  *
  * http://thread.gmane.org/gmane.linux.ide/34098
  *
- * Debounce with hotplug timing and request follow-up SRST.
+ * And bz#12176 reports that hardreset simply doesn't work on nf2.
+ * Give up on it and just don't do hardreset.
  */
 static struct ata_port_operations nv_nf2_ops = {
-        .inherits               = &nv_common_ops,
+        .inherits               = &nv_generic_ops,
         .freeze                 = nv_nf2_freeze,
         .thaw                   = nv_nf2_thaw,
-        .hardreset              = nv_noclassify_hardreset,
 };
 
-/* CK804 finally gets hardreset right */
+/* For initial probing after boot and hot plugging, hardreset mostly
+ * works fine on CK804 but curiously, reprobing on the initial port by
+ * rescanning or rmmod/insmod fails to acquire the initial D2H Reg FIS
+ * in somewhat undeterministic way.  Use noclassify hardreset.
+ */
 static struct ata_port_operations nv_ck804_ops = {
         .inherits               = &nv_common_ops,
         .freeze                 = nv_ck804_freeze,
         .thaw                   = nv_ck804_thaw,
+        .hardreset              = nv_noclassify_hardreset,
         .host_stop              = nv_ck804_host_stop,
 };
 
@@ -2516,7 +2523,7 @@ static void __exit nv_exit(void)
 module_init(nv_init);
 module_exit(nv_exit);
 module_param_named(adma, adma_enabled, bool, 0444);
-MODULE_PARM_DESC(adma, "Enable use of ADMA (Default: true)");
+MODULE_PARM_DESC(adma, "Enable use of ADMA (Default: false)");
 module_param_named(swncq, swncq_enabled, bool, 0444);
 MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: true)");