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fm10k: don't use BIT() macro where the value isn't a bitmask

PATCH New Jacob Keller 2 participants 3 messages Apr 14, 2016 – Jun 14, 2016

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Jacob Keller

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#0 lore raw

PATCH 1/1 fm10k: don't use BIT() macro where the value isn't a bitmask

The FM10K_MAX_DATA_PER_TXD is really just using a bitshift as a power of 2 operation in an efficient manner. We shouldn't represent this as a BIT() because that obscures the intention of the operation.

Signed-off-by Jacob Keller <[email protected]>
---
 drivers/net/ethernet/intel/fm10k/fm10k.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/ethernet/intel/fm10k/fm10k.h +1 -1
index fcf106e545c5..e98b86bf0ca1 100644
@@ -406,7 +406,7 @@ static inline u16 fm10k_desc_unused(struct fm10k_ring *ring)
 	 (&(((union fm10k_rx_desc *)((R)->desc))[i]))
 
 #define FM10K_MAX_TXD_PWR	14
-#define FM10K_MAX_DATA_PER_TXD	BIT(FM10K_MAX_TXD_PWR)
+#define FM10K_MAX_DATA_PER_TXD	(1u << FM10K_MAX_TXD_PWR)
 
 /* Tx Descriptors needed, worst case */
 #define TXD_USE_COUNT(S)	DIV_ROUND_UP((S), FM10K_MAX_DATA_PER_TXD)
Signature · 1 line
2.8.1.102.ga49ec4a
#1 lore raw

PATCH 1/1 fm10k: don't use BIT() macro where the value isn't a bitmask

Quoted 23 lines · Jacob Keller

The FM10K_MAX_DATA_PER_TXD is really just using a bitshift as a power of
2 operation in an efficient manner. We shouldn't represent this as a BIT()
because that obscures the intention of the operation.

Signed-off-by Jacob Keller <[email protected]>

---
?drivers/net/ethernet/intel/fm10k/fm10k.h | 2 +-
?1 file changed, 1 insertion(+), 1 deletion(-)

drivers/net/ethernet/intel/fm10k/fm10k.h +0 -0
index fcf106e545c5..e98b86bf0ca1 100644
@@ -406,7 +406,7 @@ static inline u16 fm10k_desc_unused(struct
 fm10k_ring *ring)
 ?	?(&(((union fm10k_rx_desc *)((R)->desc))[i]))

?
?#define FM10K_MAX_TXD_PWR 14

drivers/net/ethernet/intel/fm10k/fm10k.h +1 -1
-#define FM10K_MAX_DATA_PER_TXD	BIT(FM10K_MAX_TXD_PWR)
+#define FM10K_MAX_DATA_PER_TXD	(1u << FM10K_MAX_TXD_PWR)
Quoted 4 lines

?
?/* Tx Descriptors needed, worst case */
?#define TXD_USE_COUNT(S) DIV_ROUND_UP((S),
FM10K_MAX_DATA_PER_TXD)

Note: this *will* cause a checkpatch warning, but as per discussion with Alex, I think this is a false positive. I don't know if there is a good way to fix it? Perhaps we could introduce some sort of "power of 2" macro that would leave in a single place, but I really don't know if that makes a lot of sense. I also am not sure how to make checkpatch.pl avoid the complaints for specific cases such as this.

Thanks,
Jake

#2 lore raw

PATCH 1/1 fm10k: don't use BIT() macro where the value isn't a bitmask

In reply to Jacob Keller

-----Original Message-----
From: Intel-wired-lan [mailto:intel-wired-lan-bounces at lists.osuosl.org] On Behalf Of Jacob Keller
Sent: Thursday, April 14, 2016 1:17 PM
To: Intel Wired LAN <[email protected]>
Subject: [Intel-wired-lan] [PATCH] fm10k: don't use BIT() macro where the value isn't a bitmask

The FM10K_MAX_DATA_PER_TXD is really just using a bitshift as a power of
2 operation in an efficient manner. We shouldn't represent this as a BIT() because that obscures the intention of the operation.

Signed-off-by Jacob Keller <[email protected]>

---

Tested-by Krishneil Singh <[email protected]>