[PATCH v2] wifi: rtl8xxxu: Fix off by one initial RTS rate

[PATCH v2] wifi: rtl8xxxu: Fix off by one initial RTS rate

[Bitterblue Smith]

rtl8xxxu_set_basic_rates() sets the wrong initial RTS rate. It sets the
next higher rate than the one it should set, e.g. 36M instead of 24M.

The while loop was supposed to find the index of the most significant
bit which is 1, but it was copied incorrectly from the vendor driver.
Use __fls() instead.

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
---
v2:
 - Use __fls().
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 180907319e8c..2b1b633a1f96 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -4839,10 +4839,9 @@ static void rtl8xxxu_set_basic_rates(struct rtl8xxxu_priv *priv, u32 rate_cfg)
 
 	dev_dbg(&priv->udev->dev, "%s: rates %08x\n", __func__,	rate_cfg);
 
-	while (rate_cfg) {
-		rate_cfg = (rate_cfg >> 1);
-		rate_idx++;
-	}
+	if (rate_cfg)
+		rate_idx = __fls(rate_cfg);
+
 	rtl8xxxu_write8(priv, REG_INIRTS_RATE_SEL, rate_idx);
 }
 
-- 
2.43.0

RE: [PATCH v2] wifi: rtl8xxxu: Fix off by one initial RTS rate

[Ping-Ke Shih]

> -----Original Message-----
> From: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> Sent: Wednesday, January 3, 2024 3:33 AM
> To: linux-wireless@vger.kernel.org
> Cc: Jes Sorensen <Jes.Sorensen@gmail.com>; Ping-Ke Shih <pkshih@realtek.com>
> Subject: [PATCH v2] wifi: rtl8xxxu: Fix off by one initial RTS rate
> 
> rtl8xxxu_set_basic_rates() sets the wrong initial RTS rate. It sets the
> next higher rate than the one it should set, e.g. 36M instead of 24M.
> 
> The while loop was supposed to find the index of the most significant
> bit which is 1, but it was copied incorrectly from the vendor driver.
> Use __fls() instead.
> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>

Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>

Re: [PATCH v2] wifi: rtl8xxxu: Fix off by one initial RTS rate

[Kalle Valo]

Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:

> rtl8xxxu_set_basic_rates() sets the wrong initial RTS rate. It sets the
> next higher rate than the one it should set, e.g. 36M instead of 24M.
> 
> The while loop was supposed to find the index of the most significant
> bit which is 1, but it was copied incorrectly from the vendor driver.
> Use __fls() instead.
> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>

Patch applied to wireless-next.git, thanks.

80850ca041f2 wifi: rtl8xxxu: Fix off by one initial RTS rate

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/761e6836-6cd6-4930-91b6-0446834655c5@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches