HSM_ST_UNKNOWN is not used anywhere. Its value is zero and supposed to serve sanity check purpose but HSM_ST_IDLE is used for that purpose. This unused state causes confusion. After a port is initialized but before the first command is executed, the idle hsm state is UNKNOWN. However, once a command has completed, the idle hsm state is IDLE. This defeats sanity check in ata_pio_task() for the first command. This patch removes HSM_ST_UNKNOWN and consequently make HSM_ST_IDLE the default state. Signed-off-by: Tejun Heo <htejun@xxxxxxxxx> --- include/linux/libata.h | 1 - 1 file changed, 1 deletion(-) Index: work/include/linux/libata.h =================================================================== --- work.orig/include/linux/libata.h +++ work/include/linux/libata.h @@ -315,7 +315,6 @@ enum { }; enum hsm_task_states { - HSM_ST_UNKNOWN, /* state unknown */ HSM_ST_IDLE, /* no command on going */ HSM_ST, /* (waiting the device to) transfer data */ HSM_ST_LAST, /* (waiting the device to) complete command */ - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html