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iop-adma: redundant/wrong tests in iop_*_count()?

PATCH Applied Roel Kluin 2 participants 2 messages Feb 13, 2010 – Mar 1, 2010 Arm (32-bit)

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Roel Kluin

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#0 lore raw

PATCH 1/1 iop-adma: redundant/wrong tests in iop_*_count()?

When we reach the loop, len is at least 1, we only stay in the loop when len is at least MAX_BYTE_COUNT + 1, MAX_BYTE_COUNT is subtracted in each iteration. So when we leave the loop, or didn't take it, len is at least 1. Testing whether len is non-zero appears redundant.

Signed-off-by Roel Kluin <[email protected]>

---
Or are the tests off by one? Then we'll need a different patch...

arch/arm/include/asm/hardware/iop3xx-adma.h +4 -8
index 1a8c727..9b28f12 100644
@@ -366,8 +366,7 @@ static inline int iop_chan_xor_slot_count(size_t len, int src_cnt,
 		slot_cnt += *slots_per_op;
 	}
 
-	if (len)
-		slot_cnt += *slots_per_op;
+	slot_cnt += *slots_per_op;
 
 	return slot_cnt;
 }

@@ -389,8 +388,7 @@ static inline int iop_chan_zero_sum_slot_count(size_t len, int src_cnt,
 		slot_cnt += *slots_per_op;
 	}
 
-	if (len)
-		slot_cnt += *slots_per_op;
+	slot_cnt += *slots_per_op;
 
 	return slot_cnt;
 }

@@ -737,10 +735,8 @@ iop_desc_set_zero_sum_byte_count(struct iop_adma_desc_slot *desc, u32 len)
 			i += slots_per_op;
 		} while (len > IOP_ADMA_ZERO_SUM_MAX_BYTE_COUNT);
 
-		if (len) {
-			iter = iop_hw_desc_slot_idx(hw_desc, i);
-			iter->byte_count = len;
-		}
+		iter = iop_hw_desc_slot_idx(hw_desc, i);
+		iter->byte_count = len;
 	}
 }
Applied
#1 lore raw
Quoted 8 lines · Roel Kluin

When we reach the loop, len is at least 1, we only stay in the loop when len is at least MAX_BYTE_COUNT + 1, MAX_BYTE_COUNT is subtracted in each iteration. So when we leave the loop, or didn't take it, len is at least 1. Testing whether len is non-zero appears redundant.

Signed-off-by Roel Kluin <[email protected]>

---
Or are the tests off by one? Then we'll need a different patch...

No, not off by one, just redundant.

Applied, thanks.

--
Dan