[PATCH] brcmsmac: fix shift on 4 bit masked value

[PATCH] brcmsmac: fix shift on 4 bit masked value

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The calculation of offtune_val seems incorrect, the u16 value in
pi->tx_rx_cal_radio_saveregs[2] is being masked with 0xf0 and then
shifted 8 places right so that always ends up as a zero result. I
believe the intended shift was 4 bits to the right. Fix this.

[Note: not tested, I don't have the H/W]

Addresses-Coverity: ("Operands don't affect result")
Fixes: 5b435de0d786 ("net: wireless: add brcm80211 drivers")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c
index 8580a2754789..2c04bae6e21c 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c
@@ -26329,7 +26329,7 @@ static void wlc_phy_rxcal_radio_setup_nphy(struct brcms_phy *pi, u8 rx_core)
 
 					offtune_val =
 						(pi->tx_rx_cal_radio_saveregs
-						 [2] & 0xF0) >> 8;
+						 [2] & 0xF0) >> 4;
 					offtune_val =
 						(offtune_val <= 0x7) ? 0xF : 0;
 
-- 
2.30.2

Re: [PATCH] brcmsmac: fix shift on 4 bit masked value

[Kalle Valo]

Colin King <colin.king@canonical.com> writes:

> From: Colin Ian King <colin.king@canonical.com>
>
> The calculation of offtune_val seems incorrect, the u16 value in
> pi->tx_rx_cal_radio_saveregs[2] is being masked with 0xf0 and then
> shifted 8 places right so that always ends up as a zero result. I
> believe the intended shift was 4 bits to the right. Fix this.
>
> [Note: not tested, I don't have the H/W]
>
> Addresses-Coverity: ("Operands don't affect result")
> Fixes: 5b435de0d786 ("net: wireless: add brcm80211 drivers")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Can someone ack this?

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Re: [PATCH] brcmsmac: fix shift on 4 bit masked value

[Kalle Valo]

Colin King <colin.king@canonical.com> wrote:

> From: Colin Ian King <colin.king@canonical.com>
> 
> The calculation of offtune_val seems incorrect, the u16 value in
> pi->tx_rx_cal_radio_saveregs[2] is being masked with 0xf0 and then
> shifted 8 places right so that always ends up as a zero result. I
> believe the intended shift was 4 bits to the right. Fix this.
> 
> [Note: not tested, I don't have the H/W]
> 
> Addresses-Coverity: ("Operands don't affect result")
> Fixes: 5b435de0d786 ("net: wireless: add brcm80211 drivers")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

I think this needs review from someone familiar with the hardware.

Patch set to Changes Requested.

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20210318164513.19600-1-colin.king@canonical.com/

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

Re: [PATCH] brcmsmac: fix shift on 4 bit masked value

[Joe Perches]

On Sun, 2021-04-18 at 06:10 +0000, Kalle Valo wrote:
> Colin King <colin.king@canonical.com> wrote:
> 
> > From: Colin Ian King <colin.king@canonical.com>
> > 
> > The calculation of offtune_val seems incorrect, the u16 value in
> > pi->tx_rx_cal_radio_saveregs[2] is being masked with 0xf0 and then
> > shifted 8 places right so that always ends up as a zero result. I
> > believe the intended shift was 4 bits to the right. Fix this.
> > 
> > [Note: not tested, I don't have the H/W]
> > 
> > Addresses-Coverity: ("Operands don't affect result")
> > Fixes: 5b435de0d786 ("net: wireless: add brcm80211 drivers")
> > Signed-off-by: Colin Ian King <colin.king@canonical.com>
> 
> I think this needs review from someone familiar with the hardware.
> 
> Patch set to Changes Requested.

What "change" are you requesting here?

Likely there needs to be some other setting for the patch.

Perhaps "deferred" as you seem to be requesting a review
and there's no actual change necessary, just approval from
someone with the hardware and that someone test the patch.

Re: [PATCH] brcmsmac: fix shift on 4 bit masked value

[Kalle Valo]

Joe Perches <joe@perches.com> writes:

> On Sun, 2021-04-18 at 06:10 +0000, Kalle Valo wrote:
>> Colin King <colin.king@canonical.com> wrote:
>> 
>> > From: Colin Ian King <colin.king@canonical.com>
>> > 
>> > The calculation of offtune_val seems incorrect, the u16 value in
>> > pi->tx_rx_cal_radio_saveregs[2] is being masked with 0xf0 and then
>> > shifted 8 places right so that always ends up as a zero result. I
>> > believe the intended shift was 4 bits to the right. Fix this.
>> > 
>> > [Note: not tested, I don't have the H/W]
>> > 
>> > Addresses-Coverity: ("Operands don't affect result")
>> > Fixes: 5b435de0d786 ("net: wireless: add brcm80211 drivers")
>> > Signed-off-by: Colin Ian King <colin.king@canonical.com>
>> 
>> I think this needs review from someone familiar with the hardware.
>> 
>> Patch set to Changes Requested.
>
> What "change" are you requesting here?

Don't take patchwork states literally, a better name for this state
would be "Needs work" or something like that.

> Likely there needs to be some other setting for the patch.
>
> Perhaps "deferred" as you seem to be requesting a review
> and there's no actual change necessary, just approval from
> someone with the hardware and that someone test the patch.

I already asked for help on April 7th and nobody replied, so I'm
dropping this now. The patch can be resent if/when the change is
confirmed to be correct.

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