libata: zero xfer length on ATAPI data xfer IRQ is HSM violation
Treat zero xfer length as HSM violation. While at it, add
unlikely()'s to ATAPI ireason and transfer length checks.
tj: Formatted patch and added unlikely()'s.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2b57547..c9e6bd4 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5309,12 +5309,15 @@
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);