mt7601u: phy: simplify zero check on val
diff mbox series

Message ID 20190920125414.15507-1-colin.king@canonical.com
State New
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Series
  • mt7601u: phy: simplify zero check on val
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Commit Message

Colin King Sept. 20, 2019, 12:54 p.m. UTC
From: Colin Ian King <colin.king@canonical.com>

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 <colin.king@canonical.com>
---
 drivers/net/wireless/mediatek/mt7601u/phy.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

Comments

Robin Murphy Sept. 20, 2019, 1:25 p.m. UTC | #1
On 20/09/2019 13:54, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> 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 <colin.king@canonical.com>
> ---
>   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");
>
Lorenzo Bianconi Sept. 20, 2019, 1:58 p.m. UTC | #2
> From: Colin Ian King <colin.king@canonical.com>
> 
> 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 <colin.king@canonical.com>
> ---
>  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
>
Jakub Kicinski Sept. 20, 2019, 6:45 p.m. UTC | #3
On Fri, 20 Sep 2019 15:58:17 +0200, Lorenzo Bianconi wrote:
> 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.

Patch
diff mbox series

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");