[PATCH] mt7601u: phy: simplify zero check on val

Subsystems: mediatek mt7601u wireless lan driver, the rest

STALE2545d

4 messages, 4 authors, 2019-09-20 · open the first message on its own page

[PATCH] mt7601u: phy: simplify zero check on val

From: Colin King <hidden>
Date: 2019-09-20 12:54:21

From: Colin Ian King <redacted>

Currently the zero check on val to break out of a loop
is a little obscure.  Replace the val is zero and break check
with a loop while value is non-zero.

Signed-off-by: Colin Ian King <redacted>
---
 drivers/net/wireless/mediatek/mt7601u/phy.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt7601u/phy.c b/drivers/net/wireless/mediatek/mt7601u/phy.c
index 06f5702ab4bd..4e0e473caae1 100644
--- a/drivers/net/wireless/mediatek/mt7601u/phy.c
+++ b/drivers/net/wireless/mediatek/mt7601u/phy.c

@@ -213,9 +213,7 @@ int mt7601u_wait_bbp_ready(struct mt7601u_dev *dev)
 
 	do {
 		val = mt7601u_bbp_rr(dev, MT_BBP_REG_VERSION);
-		if (val && ~val)
-			break;
-	} while (--i);
+	} while (val && --i);
 
 	if (!i) {
 		dev_err(dev->dev, "Error: BBP is not ready\n");

-- 
2.20.1

Re: [PATCH] mt7601u: phy: simplify zero check on val

From: Robin Murphy <robin.murphy@arm.com>
Date: 2019-09-20 13:25:28

On 20/09/2019 13:54, Colin King wrote:

quoted hunk

From: Colin Ian King <redacted>

Currently the zero check on val to break out of a loop
is a little obscure.  Replace the val is zero and break check
with a loop while value is non-zero.

Signed-off-by: Colin Ian King <redacted>
---
  drivers/net/wireless/mediatek/mt7601u/phy.c | 4 +---
  1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt7601u/phy.c b/drivers/net/wireless/mediatek/mt7601u/phy.c
index 06f5702ab4bd..4e0e473caae1 100644
--- a/drivers/net/wireless/mediatek/mt7601u/phy.c
+++ b/drivers/net/wireless/mediatek/mt7601u/phy.c

@@ -213,9 +213,7 @@ int mt7601u_wait_bbp_ready(struct mt7601u_dev *dev)
  
  	do {
  		val = mt7601u_bbp_rr(dev, MT_BBP_REG_VERSION);
-		if (val && ~val)
-			break;

AFAICS, this effectively implements "while (val == 0 || val == 0xff)", 
which is not at all equivalent to "while(val)"... :/

Robin.

-	} while (--i);
+	} while (val && --i);
  
  	if (!i) {
  		dev_err(dev->dev, "Error: BBP is not ready\n");

Re: [PATCH] mt7601u: phy: simplify zero check on val

From: Lorenzo Bianconi <hidden>
Date: 2019-09-20 13:58:25

quoted hunk

From: Colin Ian King <redacted>

Currently the zero check on val to break out of a loop
is a little obscure.  Replace the val is zero and break check
with a loop while value is non-zero.

Signed-off-by: Colin Ian King <redacted>
---
 drivers/net/wireless/mediatek/mt7601u/phy.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt7601u/phy.c b/drivers/net/wireless/mediatek/mt7601u/phy.c
index 06f5702ab4bd..4e0e473caae1 100644
--- a/drivers/net/wireless/mediatek/mt7601u/phy.c
+++ b/drivers/net/wireless/mediatek/mt7601u/phy.c

@@ -213,9 +213,7 @@ int mt7601u_wait_bbp_ready(struct mt7601u_dev *dev)
 
 	do {
 		val = mt7601u_bbp_rr(dev, MT_BBP_REG_VERSION);
-		if (val && ~val)
-			break;

I think this is not correct since (not considering the cast) we should break
from the loop if val != 0 and val != 0xff, so the right approach I guess is:

diff --git a/drivers/net/wireless/mediatek/mt7601u/phy.c b/drivers/net/wireless/mediatek/mt7601u/phy.c
index 06f5702ab4bd..d863ab4a66c9 100644
--- a/drivers/net/wireless/mediatek/mt7601u/phy.c
+++ b/drivers/net/wireless/mediatek/mt7601u/phy.c

@@ -213,7 +213,7 @@ int mt7601u_wait_bbp_ready(struct mt7601u_dev *dev)
 
 	do {
 		val = mt7601u_bbp_rr(dev, MT_BBP_REG_VERSION);
-		if (val && ~val)
+		if (val && val != 0xff)
 			break;
 	} while (--i);

-	} while (--i);
+	} while (val && --i);
 
 	if (!i) {
 		dev_err(dev->dev, "Error: BBP is not ready\n");
-- 
2.20.1

Re: [PATCH] mt7601u: phy: simplify zero check on val

From: Jakub Kicinski <hidden>
Date: 2019-09-20 18:52:27

On Fri, 20 Sep 2019 15:58:17 +0200, Lorenzo Bianconi wrote:

quoted hunk

I think this is not correct since (not considering the cast) we should break
from the loop if val != 0 and val != 0xff, so the right approach I guess is:

diff --git a/drivers/net/wireless/mediatek/mt7601u/phy.c b/drivers/net/wireless/mediatek/mt7601u/phy.c
index 06f5702ab4bd..d863ab4a66c9 100644
--- a/drivers/net/wireless/mediatek/mt7601u/phy.c
+++ b/drivers/net/wireless/mediatek/mt7601u/phy.c

@@ -213,7 +213,7 @@ int mt7601u_wait_bbp_ready(struct mt7601u_dev *dev)
 
 	do {
 		val = mt7601u_bbp_rr(dev, MT_BBP_REG_VERSION);
-		if (val && ~val)
+		if (val && val != 0xff)
 			break;
 	} while (--i);

Yup, feel free to add my ack if you post this, Lorenzo.

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