diff mbox series

[2/2] wcn36xx: fix RX BD rate mapping for 5GHz legacy rates

Message ID 20211028223131.897548-2-benl@squareup.com (mailing list archive)
State Changes Requested
Delegated to: Kalle Valo
Headers show
Series [1/2] wcn36xx: populate band before determining rate on RX | expand

Commit Message

Benjamin Li Oct. 28, 2021, 10:31 p.m. UTC 
The linear mapping between the BD rate field and the driver's 5GHz
legacy rates table (wcn_5ghz_rates) does not only apply for the latter
four rates -- it applies to all eight rates.

Fixes: 6ea131acea98 ("wcn36xx: Fix warning due to bad rate_idx")
Signed-off-by: Benjamin Li <benl@squareup.com>
---
 drivers/net/wireless/ath/wcn36xx/txrx.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Bryan O'Donoghue Oct. 29, 2021, 12:30 a.m. UTC | #1 
On 28/10/2021 23:31, Benjamin Li wrote:
> -		    status.rate_idx >= sband->n_bitrates) {
This fix was applied because we were getting a negative index

If you want to remove that, you'll need to do something about this

status.rate_idx -= 4;

---
bod
Benjamin Li Oct. 29, 2021, 12:39 a.m. UTC | #2 
On 10/28/21 5:30 PM, Bryan O'Donoghue wrote:
> On 28/10/2021 23:31, Benjamin Li wrote:
>> -            status.rate_idx >= sband->n_bitrates) {
> This fix was applied because we were getting a negative index
> 
> If you want to remove that, you'll need to do something about this
> 
> status.rate_idx -= 4;

Hmm... so you're saying there's a FW bug where sometimes we get
bd->rate_id = 0-7 (leading to status.rate_idx = 0-3) on a 5GHz
channel?

static const struct wcn36xx_rate wcn36xx_rate_table[] = {
    /* 11b rates */
    {  10, 0, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
    {  20, 1, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
    {  55, 2, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
    { 110, 3, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },

    /* 11b SP (short preamble) */
    {  10, 0, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
    {  20, 1, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
    {  55, 2, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
    { 110, 3, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },

It sounds like we should WARN and drop the frame in that case. If
you agree I'll send a v2.

> 
> ---
> bod
Bryan O'Donoghue Oct. 29, 2021, 1:11 a.m. UTC | #3 
On 29/10/2021 01:39, Benjamin Li wrote:
> On 10/28/21 5:30 PM, Bryan O'Donoghue wrote:
>> On 28/10/2021 23:31, Benjamin Li wrote:
>>> -            status.rate_idx >= sband->n_bitrates) {
>> This fix was applied because we were getting a negative index
>>
>> If you want to remove that, you'll need to do something about this
>>
>> status.rate_idx -= 4;
> 
> Hmm... so you're saying there's a FW bug where sometimes we get
> bd->rate_id = 0-7 (leading to status.rate_idx = 0-3) on a 5GHz
> channel?

My memory is I saw a negative index as a result of the -4 offset but, it 
is quite some time ago and we have made all sorts of changes since.

> static const struct wcn36xx_rate wcn36xx_rate_table[] = {
>      /* 11b rates */
>      {  10, 0, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
>      {  20, 1, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
>      {  55, 2, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
>      { 110, 3, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
> 
>      /* 11b SP (short preamble) */
>      {  10, 0, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
>      {  20, 1, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
>      {  55, 2, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
>      { 110, 3, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
> 
> It sounds like we should WARN and drop the frame in that case. If
> you agree I'll send a v2.

So,

Let me see if I can replicate the previous bug - tomorrow - later this 
morning in fact - in this timezone, and I'll get back to you.

---
bod
kernel test robot Oct. 29, 2021, 6:30 p.m. UTC | #4 
Hi Benjamin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on kvalo-wireless-drivers-next/master]
[also build test WARNING on kvalo-ath/ath-next kvalo-wireless-drivers/master v5.15-rc7 next-20211029]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Benjamin-Li/wcn36xx-populate-band-before-determining-rate-on-RX/20211029-064020
base:   https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next.git master
config: arm64-defconfig (attached as .config)
compiler: aarch64-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/4713a80ea03fc60eaa4de959a3ec73154493f35a
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Benjamin-Li/wcn36xx-populate-band-before-determining-rate-on-RX/20211029-064020
        git checkout 4713a80ea03fc60eaa4de959a3ec73154493f35a
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/net/wireless/ath/wcn36xx/txrx.c: In function 'wcn36xx_rx_skb':
>> drivers/net/wireless/ath/wcn36xx/txrx.c:275:42: warning: variable 'sband' set but not used [-Wunused-but-set-variable]
     275 |         struct ieee80211_supported_band *sband;
         |                                          ^~~~~


vim +/sband +275 drivers/net/wireless/ath/wcn36xx/txrx.c

a224b47ab36d7d Loic Poulain     2021-10-25  268  
8e84c25821698b Eugene Krasnikov 2013-10-08  269  int wcn36xx_rx_skb(struct wcn36xx *wcn, struct sk_buff *skb)
8e84c25821698b Eugene Krasnikov 2013-10-08  270  {
8e84c25821698b Eugene Krasnikov 2013-10-08  271  	struct ieee80211_rx_status status;
0aa90483f23e79 Loic Poulain     2020-06-15  272  	const struct wcn36xx_rate *rate;
8e84c25821698b Eugene Krasnikov 2013-10-08  273  	struct ieee80211_hdr *hdr;
8e84c25821698b Eugene Krasnikov 2013-10-08  274  	struct wcn36xx_rx_bd *bd;
6ea131acea9802 Loic Poulain     2020-08-29 @275  	struct ieee80211_supported_band *sband;
8e84c25821698b Eugene Krasnikov 2013-10-08  276  	u16 fc, sn;
8e84c25821698b Eugene Krasnikov 2013-10-08  277  
8e84c25821698b Eugene Krasnikov 2013-10-08  278  	/*
8e84c25821698b Eugene Krasnikov 2013-10-08  279  	 * All fields must be 0, otherwise it can lead to
8e84c25821698b Eugene Krasnikov 2013-10-08  280  	 * unexpected consequences.
8e84c25821698b Eugene Krasnikov 2013-10-08  281  	 */
8e84c25821698b Eugene Krasnikov 2013-10-08  282  	memset(&status, 0, sizeof(status));
8e84c25821698b Eugene Krasnikov 2013-10-08  283  
8e84c25821698b Eugene Krasnikov 2013-10-08  284  	bd = (struct wcn36xx_rx_bd *)skb->data;
8e84c25821698b Eugene Krasnikov 2013-10-08  285  	buff_to_be((u32 *)bd, sizeof(*bd)/sizeof(u32));
8e84c25821698b Eugene Krasnikov 2013-10-08  286  	wcn36xx_dbg_dump(WCN36XX_DBG_RX_DUMP,
8e84c25821698b Eugene Krasnikov 2013-10-08  287  			 "BD   <<< ", (char *)bd,
8e84c25821698b Eugene Krasnikov 2013-10-08  288  			 sizeof(struct wcn36xx_rx_bd));
8e84c25821698b Eugene Krasnikov 2013-10-08  289  
a224b47ab36d7d Loic Poulain     2021-10-25  290  	if (bd->pdu.mpdu_data_off <= bd->pdu.mpdu_header_off ||
a224b47ab36d7d Loic Poulain     2021-10-25  291  	    bd->pdu.mpdu_len < bd->pdu.mpdu_header_len)
a224b47ab36d7d Loic Poulain     2021-10-25  292  		goto drop;
a224b47ab36d7d Loic Poulain     2021-10-25  293  
a224b47ab36d7d Loic Poulain     2021-10-25  294  	if (bd->asf && !bd->esf) { /* chained A-MSDU chunks */
a224b47ab36d7d Loic Poulain     2021-10-25  295  		/* Sanity check */
a224b47ab36d7d Loic Poulain     2021-10-25  296  		if (bd->pdu.mpdu_data_off + bd->pdu.mpdu_len > WCN36XX_PKT_SIZE)
a224b47ab36d7d Loic Poulain     2021-10-25  297  			goto drop;
a224b47ab36d7d Loic Poulain     2021-10-25  298  
a224b47ab36d7d Loic Poulain     2021-10-25  299  		skb_put(skb, bd->pdu.mpdu_data_off + bd->pdu.mpdu_len);
a224b47ab36d7d Loic Poulain     2021-10-25  300  		skb_pull(skb, bd->pdu.mpdu_data_off);
a224b47ab36d7d Loic Poulain     2021-10-25  301  
a224b47ab36d7d Loic Poulain     2021-10-25  302  		/* Only set status for first chained BD (with mac header) */
a224b47ab36d7d Loic Poulain     2021-10-25  303  		goto done;
a224b47ab36d7d Loic Poulain     2021-10-25  304  	}
a224b47ab36d7d Loic Poulain     2021-10-25  305  
a224b47ab36d7d Loic Poulain     2021-10-25  306  	if (bd->pdu.mpdu_header_off < sizeof(*bd) ||
a224b47ab36d7d Loic Poulain     2021-10-25  307  	    bd->pdu.mpdu_header_off + bd->pdu.mpdu_len > WCN36XX_PKT_SIZE)
a224b47ab36d7d Loic Poulain     2021-10-25  308  		goto drop;
a224b47ab36d7d Loic Poulain     2021-10-25  309  
8e84c25821698b Eugene Krasnikov 2013-10-08  310  	skb_put(skb, bd->pdu.mpdu_header_off + bd->pdu.mpdu_len);
8e84c25821698b Eugene Krasnikov 2013-10-08  311  	skb_pull(skb, bd->pdu.mpdu_header_off);
8e84c25821698b Eugene Krasnikov 2013-10-08  312  
886039036c2004 Bjorn Andersson  2017-01-11  313  	hdr = (struct ieee80211_hdr *) skb->data;
886039036c2004 Bjorn Andersson  2017-01-11  314  	fc = __le16_to_cpu(hdr->frame_control);
886039036c2004 Bjorn Andersson  2017-01-11  315  	sn = IEEE80211_SEQ_TO_SN(__le16_to_cpu(hdr->seq_ctrl));
886039036c2004 Bjorn Andersson  2017-01-11  316  
886039036c2004 Bjorn Andersson  2017-01-11  317  	status.mactime = 10;
8e84c25821698b Eugene Krasnikov 2013-10-08  318  	status.signal = -get_rssi0(bd);
8e84c25821698b Eugene Krasnikov 2013-10-08  319  	status.antenna = 1;
8e84c25821698b Eugene Krasnikov 2013-10-08  320  	status.flag = 0;
8e84c25821698b Eugene Krasnikov 2013-10-08  321  	status.rx_flags = 0;
8e84c25821698b Eugene Krasnikov 2013-10-08  322  	status.flag |= RX_FLAG_IV_STRIPPED |
8e84c25821698b Eugene Krasnikov 2013-10-08  323  		       RX_FLAG_MMIC_STRIPPED |
8e84c25821698b Eugene Krasnikov 2013-10-08  324  		       RX_FLAG_DECRYPTED;
8e84c25821698b Eugene Krasnikov 2013-10-08  325  
7fdd69c5af2160 Johannes Berg    2017-04-26  326  	wcn36xx_dbg(WCN36XX_DBG_RX, "status.flags=%x\n", status.flag);
8e84c25821698b Eugene Krasnikov 2013-10-08  327  
cec59cdeb543bd Benjamin Li      2021-10-28  328  	if (bd->scan_learn) {
cec59cdeb543bd Benjamin Li      2021-10-28  329  		/* If packet originate from hardware scanning, extract the
cec59cdeb543bd Benjamin Li      2021-10-28  330  		 * band/channel from bd descriptor.
cec59cdeb543bd Benjamin Li      2021-10-28  331  		 */
cec59cdeb543bd Benjamin Li      2021-10-28  332  		u8 hwch = (bd->reserved0 << 4) + bd->rx_ch;
cec59cdeb543bd Benjamin Li      2021-10-28  333  
cec59cdeb543bd Benjamin Li      2021-10-28  334  		if (bd->rf_band != 1 && hwch <= sizeof(ab_rx_ch_map) && hwch >= 1) {
cec59cdeb543bd Benjamin Li      2021-10-28  335  			status.band = NL80211_BAND_5GHZ;
cec59cdeb543bd Benjamin Li      2021-10-28  336  			status.freq = ieee80211_channel_to_frequency(ab_rx_ch_map[hwch - 1],
cec59cdeb543bd Benjamin Li      2021-10-28  337  								     status.band);
cec59cdeb543bd Benjamin Li      2021-10-28  338  		} else {
cec59cdeb543bd Benjamin Li      2021-10-28  339  			status.band = NL80211_BAND_2GHZ;
cec59cdeb543bd Benjamin Li      2021-10-28  340  			status.freq = ieee80211_channel_to_frequency(hwch, status.band);
cec59cdeb543bd Benjamin Li      2021-10-28  341  		}
cec59cdeb543bd Benjamin Li      2021-10-28  342  	} else {
cec59cdeb543bd Benjamin Li      2021-10-28  343  		status.band = WCN36XX_BAND(wcn);
cec59cdeb543bd Benjamin Li      2021-10-28  344  		status.freq = WCN36XX_CENTER_FREQ(wcn);
cec59cdeb543bd Benjamin Li      2021-10-28  345  	}
cec59cdeb543bd Benjamin Li      2021-10-28  346  
0aa90483f23e79 Loic Poulain     2020-06-15  347  	if (bd->rate_id < ARRAY_SIZE(wcn36xx_rate_table)) {
0aa90483f23e79 Loic Poulain     2020-06-15  348  		rate = &wcn36xx_rate_table[bd->rate_id];
0aa90483f23e79 Loic Poulain     2020-06-15  349  		status.encoding = rate->encoding;
0aa90483f23e79 Loic Poulain     2020-06-15  350  		status.enc_flags = rate->encoding_flags;
0aa90483f23e79 Loic Poulain     2020-06-15  351  		status.bw = rate->bw;
0aa90483f23e79 Loic Poulain     2020-06-15  352  		status.rate_idx = rate->mcs_or_legacy_index;
6ea131acea9802 Loic Poulain     2020-08-29  353  		sband = wcn->hw->wiphy->bands[status.band];
1af05d43b9bef4 Bryan O'Donoghue 2020-08-29  354  		status.nss = 1;
6ea131acea9802 Loic Poulain     2020-08-29  355  
6ea131acea9802 Loic Poulain     2020-08-29  356  		if (status.band == NL80211_BAND_5GHZ &&
4713a80ea03fc6 Benjamin Li      2021-10-28  357  		    status.encoding == RX_ENC_LEGACY) {
6ea131acea9802 Loic Poulain     2020-08-29  358  			/* no dsss rates in 5Ghz rates table */
6ea131acea9802 Loic Poulain     2020-08-29  359  			status.rate_idx -= 4;
6ea131acea9802 Loic Poulain     2020-08-29  360  		}
0aa90483f23e79 Loic Poulain     2020-06-15  361  	} else {
0aa90483f23e79 Loic Poulain     2020-06-15  362  		status.encoding = 0;
0aa90483f23e79 Loic Poulain     2020-06-15  363  		status.bw = 0;
0aa90483f23e79 Loic Poulain     2020-06-15  364  		status.enc_flags = 0;
0aa90483f23e79 Loic Poulain     2020-06-15  365  		status.rate_idx = 0;
0aa90483f23e79 Loic Poulain     2020-06-15  366  	}
0aa90483f23e79 Loic Poulain     2020-06-15  367  
8678fd31f2d3eb Loic Poulain     2021-08-26  368  	if (ieee80211_is_beacon(hdr->frame_control) ||
8678fd31f2d3eb Loic Poulain     2021-08-26  369  	    ieee80211_is_probe_resp(hdr->frame_control))
8678fd31f2d3eb Loic Poulain     2021-08-26  370  		status.boottime_ns = ktime_get_boottime_ns();
8678fd31f2d3eb Loic Poulain     2021-08-26  371  
8e84c25821698b Eugene Krasnikov 2013-10-08  372  	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
8e84c25821698b Eugene Krasnikov 2013-10-08  373  
8e84c25821698b Eugene Krasnikov 2013-10-08  374  	if (ieee80211_is_beacon(hdr->frame_control)) {
8e84c25821698b Eugene Krasnikov 2013-10-08  375  		wcn36xx_dbg(WCN36XX_DBG_BEACON, "beacon skb %p len %d fc %04x sn %d\n",
8e84c25821698b Eugene Krasnikov 2013-10-08  376  			    skb, skb->len, fc, sn);
8e84c25821698b Eugene Krasnikov 2013-10-08  377  		wcn36xx_dbg_dump(WCN36XX_DBG_BEACON_DUMP, "SKB <<< ",
8e84c25821698b Eugene Krasnikov 2013-10-08  378  				 (char *)skb->data, skb->len);
8e84c25821698b Eugene Krasnikov 2013-10-08  379  	} else {
8e84c25821698b Eugene Krasnikov 2013-10-08  380  		wcn36xx_dbg(WCN36XX_DBG_RX, "rx skb %p len %d fc %04x sn %d\n",
8e84c25821698b Eugene Krasnikov 2013-10-08  381  			    skb, skb->len, fc, sn);
8e84c25821698b Eugene Krasnikov 2013-10-08  382  		wcn36xx_dbg_dump(WCN36XX_DBG_RX_DUMP, "SKB <<< ",
8e84c25821698b Eugene Krasnikov 2013-10-08  383  				 (char *)skb->data, skb->len);
8e84c25821698b Eugene Krasnikov 2013-10-08  384  	}
8e84c25821698b Eugene Krasnikov 2013-10-08  385  
a224b47ab36d7d Loic Poulain     2021-10-25  386  done:
a224b47ab36d7d Loic Poulain     2021-10-25  387  	/*  Chained AMSDU ? slow path */
a224b47ab36d7d Loic Poulain     2021-10-25  388  	if (unlikely(bd->asf && !(bd->lsf && bd->esf))) {
a224b47ab36d7d Loic Poulain     2021-10-25  389  		if (bd->esf && !skb_queue_empty(&wcn->amsdu)) {
a224b47ab36d7d Loic Poulain     2021-10-25  390  			wcn36xx_err("Discarding non complete chain");
a224b47ab36d7d Loic Poulain     2021-10-25  391  			__skb_queue_purge_irq(&wcn->amsdu);
a224b47ab36d7d Loic Poulain     2021-10-25  392  		}
a224b47ab36d7d Loic Poulain     2021-10-25  393  
a224b47ab36d7d Loic Poulain     2021-10-25  394  		__skb_queue_tail(&wcn->amsdu, skb);
a224b47ab36d7d Loic Poulain     2021-10-25  395  
a224b47ab36d7d Loic Poulain     2021-10-25  396  		if (!bd->lsf)
a224b47ab36d7d Loic Poulain     2021-10-25  397  			return 0; /* Not the last AMSDU, wait for more */
a224b47ab36d7d Loic Poulain     2021-10-25  398  
a224b47ab36d7d Loic Poulain     2021-10-25  399  		skb = wcn36xx_unchain_msdu(&wcn->amsdu);
a224b47ab36d7d Loic Poulain     2021-10-25  400  		if (!skb)
a224b47ab36d7d Loic Poulain     2021-10-25  401  			goto drop;
a224b47ab36d7d Loic Poulain     2021-10-25  402  	}
a224b47ab36d7d Loic Poulain     2021-10-25  403  
8e84c25821698b Eugene Krasnikov 2013-10-08  404  	ieee80211_rx_irqsafe(wcn->hw, skb);
8e84c25821698b Eugene Krasnikov 2013-10-08  405  
8e84c25821698b Eugene Krasnikov 2013-10-08  406  	return 0;
a224b47ab36d7d Loic Poulain     2021-10-25  407  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Kalle Valo Nov. 1, 2021, 1 p.m. UTC | #5 
Benjamin Li <benl@squareup.com> writes:

> On 10/28/21 5:30 PM, Bryan O'Donoghue wrote:
>> On 28/10/2021 23:31, Benjamin Li wrote:
>>> -            status.rate_idx >= sband->n_bitrates) {
>> This fix was applied because we were getting a negative index
>> 
>> If you want to remove that, you'll need to do something about this
>> 
>> status.rate_idx -= 4;
>
> Hmm... so you're saying there's a FW bug where sometimes we get
> bd->rate_id = 0-7 (leading to status.rate_idx = 0-3) on a 5GHz
> channel?
>
> static const struct wcn36xx_rate wcn36xx_rate_table[] = {
>     /* 11b rates */
>     {  10, 0, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
>     {  20, 1, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
>     {  55, 2, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
>     { 110, 3, RX_ENC_LEGACY, 0, RATE_INFO_BW_20 },
>
>     /* 11b SP (short preamble) */
>     {  10, 0, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
>     {  20, 1, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
>     {  55, 2, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
>     { 110, 3, RX_ENC_LEGACY, RX_ENC_FLAG_SHORTPRE, RATE_INFO_BW_20 },
>
> It sounds like we should WARN and drop the frame in that case. If
> you agree I'll send a v2.

BTW, please avoid using WARN() family of functions in the data path as
that can cause host crashes due to too much spamming in the logs. A some
kind of ratelimited version of an error message is much safer. For
example ath11k_warn() is ratelimited, maybe wcn36xx_warn() should be as
well?
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/wcn36xx/txrx.c b/drivers/net/wireless/ath/wcn36xx/txrx.c
index f0a9f069a92a9..b4a36acdaca74 100644
--- a/drivers/net/wireless/ath/wcn36xx/txrx.c
+++ b/drivers/net/wireless/ath/wcn36xx/txrx.c
@@ -354,8 +354,7 @@  int wcn36xx_rx_skb(struct wcn36xx *wcn, struct sk_buff *skb)
 		status.nss = 1;
 
 		if (status.band == NL80211_BAND_5GHZ &&
-		    status.encoding == RX_ENC_LEGACY &&
-		    status.rate_idx >= sband->n_bitrates) {
+		    status.encoding == RX_ENC_LEGACY) {
 			/* no dsss rates in 5Ghz rates table */
 			status.rate_idx -= 4;
 		}