Re: [PATCH] mac80211: invoke software scan when hardware scan returns EPERM

Re: [PATCH] mac80211: invoke software scan when hardware scan returns EPERM

[Kalle Valo]

Sushant Kumar Mishra <sushant2k1513@gmail.com> writes:

> From: Sanjay Kumar Konduri <sanjay.konduri@redpinesignals.com>
>
> Currently, software scan in mac80211 is used by drivers, which don't
> implement hardware scan. However some drivers which have implemented
> hardware scan may also sometimes want to use software scan in mac80211.
> Such drivers can return '-EPERM' and ask mac80211 to fallback to
> software scan with this patch.
>
> Signed-off-by: Sanjay Kumar Konduri <sanjay.konduri@redpinesignals.com>
> Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
> Signed-off-by: Sushant Kumar Mishra <sushant.mishra@redpinesignals.com>

This and the following rsi patch should in the same patchset as there's
a dependency. This being patch 1 and "rsi: add support for hardware scan
offload" patch 2.

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

Also Johanne's address (Johannes@codeaurora.org, "Berg
<johannes"@sipsolutions.net) looked bogus so I fixed it.

-- 
Kalle Valo

Re: [v2] rsi: add support for hardware scan offload

[Kalle Valo]

Sushant Kumar Mishra <sushant2k1513@gmail.com> writes:

> From: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
>
> With the current approach of scanning, roaming delays are observed.
> Firmware has support for back ground scanning. To get this advantage,
> mac80211 hardware scan is implemented, which decides type of scan to
> do based on connected state.
>
> When station is in not connected state, this returns operation not
> supported(-EPERM) to trigger software scan in mac80211. In case of
> connected state background scan will be triggered.
>
> Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
> Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
> Signed-off-by: Sushant Kumar Mishra <sushant.mishra@redpinesignals.com>

This patch looks much better, thanks. But the subject should be:

[PATCH v2 2/2] rsi: add support for hardware scan offload

> +static int rsi_prepare_probe_request(struct rsi_common *common,
> +				     struct cfg80211_scan_request *scan_req,
> +				     u8 n_ssid, u8 channel, u8 *pbreq,
> +				     u16 *pbreq_len, struct ieee80211_vif *vif)
> +{
> +	struct cfg80211_ssid *ssid_info;
> +	struct ieee80211_hdr *hdr = NULL;
> +	u8 *pos;
> +
> +	if (common->priv->sc_nvifs <= 0)
> +		return -ENODEV;
> +	if (!scan_req)
> +		return -EINVAL;
> +	if (!scan_req->ssids)
> +		return -EINVAL;
> +	ssid_info = &scan_req->ssids[n_ssid];
> +	hdr = (struct ieee80211_hdr *)pbreq;
> +	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
> +					 IEEE80211_STYPE_PROBE_REQ);
> +	hdr->duration_id = 0x0;
> +	memset(hdr->addr1, 0xff, ETH_ALEN);
> +	memset(hdr->addr3, 0xff, ETH_ALEN);
> +	ether_addr_copy(hdr->addr2, vif->addr);
> +	hdr->seq_ctrl = 0x00;
> +	pos = (u8 *)hdr + MIN_802_11_HDR_LEN;
> +
> +	*pos++ = WLAN_EID_SSID;
> +	*pos++ = ssid_info->ssid_len;
> +	if (ssid_info->ssid_len)
> +		memcpy(pos, ssid_info->ssid, ssid_info->ssid_len);
> +	pos += ssid_info->ssid_len;
> +
> +	if (scan_req->ie_len)
> +		memcpy(pos, scan_req->ie, scan_req->ie_len);
> +	pos += scan_req->ie_len;
> +	*pbreq_len = pos - pbreq;
> +
> +	return 0;
> +}

But can't you use ieee80211_probereq_get()?

-- 
Kalle Valo

Re: [v2] rsi: add support for hardware scan offload

[sushant kumar mishra]

On Wed, May 16, 2018 at 5:03 PM, Kalle Valo <kvalo@codeaurora.org> wrote:
> Sushant Kumar Mishra <sushant2k1513@gmail.com> writes:
>
>> From: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
>>
>> With the current approach of scanning, roaming delays are observed.
>> Firmware has support for back ground scanning. To get this advantage,
>> mac80211 hardware scan is implemented, which decides type of scan to
>> do based on connected state.
>>
>> When station is in not connected state, this returns operation not
>> supported(-EPERM) to trigger software scan in mac80211. In case of
>> connected state background scan will be triggered.
>>
>> Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
>> Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
>> Signed-off-by: Sushant Kumar Mishra <sushant.mishra@redpinesignals.com>
>
> This patch looks much better, thanks. But the subject should be:
>
> [PATCH v2 2/2] rsi: add support for hardware scan offload
>
>> +static int rsi_prepare_probe_request(struct rsi_common *common,
>> +                                  struct cfg80211_scan_request *scan_req,
>> +                                  u8 n_ssid, u8 channel, u8 *pbreq,
>> +                                  u16 *pbreq_len, struct ieee80211_vif *vif)
>> +{
>> +     struct cfg80211_ssid *ssid_info;
>> +     struct ieee80211_hdr *hdr = NULL;
>> +     u8 *pos;
>> +
>> +     if (common->priv->sc_nvifs <= 0)
>> +             return -ENODEV;
>> +     if (!scan_req)
>> +             return -EINVAL;
>> +     if (!scan_req->ssids)
>> +             return -EINVAL;
>> +     ssid_info = &scan_req->ssids[n_ssid];
>> +     hdr = (struct ieee80211_hdr *)pbreq;
>> +     hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
>> +                                      IEEE80211_STYPE_PROBE_REQ);
>> +     hdr->duration_id = 0x0;
>> +     memset(hdr->addr1, 0xff, ETH_ALEN);
>> +     memset(hdr->addr3, 0xff, ETH_ALEN);
>> +     ether_addr_copy(hdr->addr2, vif->addr);
>> +     hdr->seq_ctrl = 0x00;
>> +     pos = (u8 *)hdr + MIN_802_11_HDR_LEN;
>> +
>> +     *pos++ = WLAN_EID_SSID;
>> +     *pos++ = ssid_info->ssid_len;
>> +     if (ssid_info->ssid_len)
>> +             memcpy(pos, ssid_info->ssid, ssid_info->ssid_len);
>> +     pos += ssid_info->ssid_len;
>> +
>> +     if (scan_req->ie_len)
>> +             memcpy(pos, scan_req->ie, scan_req->ie_len);
>> +     pos += scan_req->ie_len;
>> +     *pbreq_len = pos - pbreq;
>> +
>> +     return 0;
>> +}
>
> But can't you use ieee80211_probereq_get()?

Thanks for the input. We ll address this in updated version.
Regards,
Sushant