libata: zero xfer length on ATAPI data xfer IRQ is HSM violation

[deliverable/linux.git] / drivers / ata / libata-core.c

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2b57547bd740478379d6ec9740191ca56240815d..c9e6bd4d0686e1c3a349ec985091231c94aa5ec6 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5309,12 +5309,15 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc)
        bytes = (bc_hi << 8) | bc_lo;
 
        /* shall be cleared to zero, indicating xfer of data */
-       if (ireason & (1 << 0))
+       if (unlikely(ireason & (1 << 0)))
                goto err_out;
 
        /* make sure transfer direction matches expected */
        i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
-       if (do_write != i_write)
+       if (unlikely(do_write != i_write))
+               goto err_out;
+
+       if (unlikely(!bytes))
                goto err_out;
 
        VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);