diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index 7c69090..f130652 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -1196,7 +1196,7 @@
 				  be32_to_cpu(hdr->bth[0]) & 0xff);
 		else {
 			/*
-			 * error packet, type of error	unknown.
+			 * error packet, type of error unknown.
 			 * Probably type 3, but we don't know, so don't
 			 * even try to print the opcode, etc.
 			 */
diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index 2a75faf..9e5714d6 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -1050,11 +1050,6 @@
 
 	phys = dd->ipath_physaddr + piobufs;
 
-	/*
-	 * Don't mark this as non-cached, or we don't get the
-	 * write combining behavior we want on the PIO buffers!
-	 */
-
 #if defined(__powerpc__)
 	/* There isn't a generic way to specify writethrough mappings */
 	pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
diff --git a/drivers/infiniband/hw/ipath/ipath_iba6110.c b/drivers/infiniband/hw/ipath/ipath_iba6110.c
index ce85879..dffb682 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6110.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6110.c
@@ -1022,7 +1022,8 @@
 	do {
 		u8 cap_type;
 
-		/* the HT capability type byte is 3 bytes after the
+		/*
+		 * The HT capability type byte is 3 bytes after the
 		 * capability byte.
 		 */
 		if (pci_read_config_byte(pdev, pos + 3, &cap_type)) {
diff --git a/drivers/infiniband/hw/ipath/ipath_iba6120.c b/drivers/infiniband/hw/ipath/ipath_iba6120.c
index 97ae117..66925b2 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6120.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6120.c
@@ -535,7 +535,7 @@
 
 	if (hwerrs & INFINIPATH_HWE_SERDESPLLFAILED) {
 		/*
-		 * If it occurs, it is left masked since the eternal
+		 * If it occurs, it is left masked since the external
 		 * interface is unused
 		 */
 		dd->ipath_hwerrmask &= ~INFINIPATH_HWE_SERDESPLLFAILED;
diff --git a/drivers/infiniband/hw/ipath/ipath_keys.c b/drivers/infiniband/hw/ipath/ipath_keys.c
index 85a4aef..8f32b17 100644
--- a/drivers/infiniband/hw/ipath/ipath_keys.c
+++ b/drivers/infiniband/hw/ipath/ipath_keys.c
@@ -128,9 +128,8 @@
 	int ret;
 
 	/*
-	 * We use LKEY == zero to mean a physical kmalloc() address.
-	 * This is a bit of a hack since we rely on dma_map_single()
-	 * being reversible by calling bus_to_virt().
+	 * We use LKEY == zero for kernel virtual addresses
+	 * (see ipath_get_dma_mr and ipath_dma.c).
 	 */
 	if (sge->lkey == 0) {
 		struct ipath_pd *pd = to_ipd(qp->ibqp.pd);
diff --git a/drivers/infiniband/hw/ipath/ipath_verbs.c b/drivers/infiniband/hw/ipath/ipath_verbs.c
index a2baa61..904ff15 100644
--- a/drivers/infiniband/hw/ipath/ipath_verbs.c
+++ b/drivers/infiniband/hw/ipath/ipath_verbs.c
@@ -943,7 +943,7 @@
  * ipath_verbs_send - send a packet
  * @qp: the QP to send on
  * @hdr: the packet header
- * @hdrwords: the number of words in the header
+ * @hdrwords: the number of 32-bit words in the header
  * @ss: the SGE to send
  * @len: the length of the packet in bytes
  */
@@ -955,7 +955,10 @@
 	int ret;
 	u32 dwords = (len + 3) >> 2;
 
-	/* +1 is for the qword padding of pbc */
+	/*
+	 * Calculate the send buffer trigger address.
+	 * The +1 counts for the pbc control dword following the pbc length.
+	 */
 	plen = hdrwords + dwords + 1;
 
 	/* Drop non-VL15 packets if we are not in the active state */