linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Felix Fietkau <nbd@openwrt.org>
To: Bala Shanmugam <bkamatch@qca.qualcomm.com>
Cc: linville@tuxdriver.com, linux-wireless@vger.kernel.org
Subject: Re: [PATCH v2] ath9k: Do not enable ANT diversity if ANT control bit is not set
Date: Tue, 30 Oct 2012 14:11:56 +0100	[thread overview]
Message-ID: <508FD21C.6080707@openwrt.org> (raw)
In-Reply-To: <1351595612-3566-1-git-send-email-bkamatch@qca.qualcomm.com>

On 2012-10-30 12:13 PM, Bala Shanmugam wrote:
> RvR test is not good when ANT control bit is not set so
> enable ANT diversity only when ANT control bit is set.
> 
> Signed-off-by: Bala Shanmugam <bkamatch@qca.qualcomm.com>
I don't really like this patch; not only is the description very vague,
but it seems to me that the checks are done at the wrong place.

Further comments below...

> --- a/drivers/net/wireless/ath/ath9k/ar9003_phy.c
> +++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
> @@ -1340,10 +1340,9 @@ static void ar9003_hw_antctrl_shared_chain_lnadiv(struct ath_hw *ah,
>  	regval = REG_READ(ah, AR_PHY_MC_GAIN_CTRL);
>  	regval &= (~AR_ANT_DIV_CTRL_ALL);
>  	regval |= (ant_div_ctl1 & 0x3f) << AR_ANT_DIV_CTRL_ALL_S;
> -	regval &= ~AR_PHY_ANT_DIV_LNADIV;
> -	regval |= ((ant_div_ctl1 >> 6) & 0x1) << AR_PHY_ANT_DIV_LNADIV_S;
>  
> -	if (enable)
> +	if (enable &&
> +	    (ant_div_ctl1 & AR_EEP_ANT_DIV_ENABLE))
>  		regval |= AR_ANT_DIV_ENABLE;
>  
>  	REG_WRITE(ah, AR_PHY_MC_GAIN_CTRL, regval);
The code should check much earlier (preferably somewhere in the eeprom
code) if diversity is available at all, and set a capability
accordingly, so that it doesn't even call this function with
enable==true if no diversity is available.

> @@ -1352,12 +1351,15 @@ static void ar9003_hw_antctrl_shared_chain_lnadiv(struct ath_hw *ah,
>  	regval &= ~AR_FAST_DIV_ENABLE;
>  	regval |= ((ant_div_ctl1 >> 7) & 0x1) << AR_FAST_DIV_ENABLE_S;
>  
> -	if (enable)
> +	if (enable &&
> +	    (ant_div_ctl1 & AR_EEP_FAST_DIV_ENABLE))
>  		regval |= AR_FAST_DIV_ENABLE;
>  
It would be much simpler to just remove the if statement and the line
below it. This would be equivalent to what you're doing because of this:
  	regval |= ((ant_div_ctl1 >> 7) & 0x1) << AR_FAST_DIV_ENABLE_S;

- Felix

      reply	other threads:[~2012-10-30 13:12 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-30 11:13 [PATCH v2] ath9k: Do not enable ANT diversity if ANT control bit is not set Bala Shanmugam
2012-10-30 13:11 ` Felix Fietkau [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=508FD21C.6080707@openwrt.org \
    --to=nbd@openwrt.org \
    --cc=bkamatch@qca.qualcomm.com \
    --cc=linux-wireless@vger.kernel.org \
    --cc=linville@tuxdriver.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).