Re: PATCH [1/1]: wireless: mac80211_hwsim: support/ignore power state changes

Re: PATCH [1/1]: wireless: mac80211_hwsim: support/ignore power state changes

[Johannes Berg]

> indicate power state support. This in turn causes VTS failures because
> the WiFi HAL can't enable power saving mode. The remaining code is
> just there to deal with the incoming state change request.

What's VTS?

johannes

Re: PATCH [1/1]: wireless: mac80211_hwsim: support/ignore power state changes

[Bjoern Johansson]

On Thu, Apr 5, 2018 at 1:35 AM Johannes Berg <johannes@sipsolutions.net>
wrote:


> > indicate power state support. This in turn causes VTS failures because
> > the WiFi HAL can't enable power saving mode. The remaining code is
> > just there to deal with the incoming state change request.

> What's VTS?

> johannes

That message wasn't really intended as a commit message but an internal
clarification of why we needed this fix but I'll try to give an
explanation. VTS is the Android Vendor Test Suite (
https://source.android.com/compatibility/vts/). It's one of the test suites
required by Google to be able to put the Play Store on an Android device.
The tests verify that the device and APIs behave in the expected,
documented way (hopefully) without bugs or unexpected behavior. One of the
tests requires that WiFi can be placed in power saving mode to improve
battery life. Battery life is of course not really an issue for an emulator
but the tests cover other devices where this is important.

Regards,
Bjoern

PATCH [1/1]: wireless: mac80211_hwsim: support/ignore power state changes

[Roman Kiryanov]

From: Bjoern Johansson <bjoernj@google.com>

Indicate support for power state changes and handle them by calling an
empty function.
The important part is "ieee80211_hw_set(hw, SUPPORTS_PS);" at the
bottom of the diff. Without this upper layers in the kernel will return an
error code when trying to set the power state because the driver doesn't
indicate power state support. This in turn causes VTS
(Android Vendor Test Suite) failures because the WiFi HAL can't enable
power saving mode. The remaining code is just there to deal with the
incoming state change request.

Signed-off-by: Bjoern Johansson <bjoernj@google.com>
Signed-off-by: Lingfeng Yang <lfy@google.com>
Signed-off-by: Roman Kiryanov <rkir@google.com>
---
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -1637,6 +1637,11 @@ static const char * const hwsim_chanwidths[] = {
         [NL80211_CHAN_WIDTH_160] = "vht160",
  };

+static void mac80211_power_state_changed(bool enabled)
+{
+       /* TODO: Do something when the power state changes */
+}
+
  static int mac80211_hwsim_config(struct ieee80211_hw *hw, u32 changed)
  {
         struct mac80211_hwsim_data *data = hw->priv;
@@ -1649,6 +1654,11 @@ static int mac80211_hwsim_config(struct ieee80211_hw
*hw, u32 changed)
         };
         int idx;

+       if (changed & IEEE80211_CONF_CHANGE_PS) {
+               bool enabled = (conf->flags & IEEE80211_CONF_PS) != 0;
+               mac80211_power_state_changed(enabled);
+       }
+
         if (conf->chandef.chan)
                 wiphy_dbg(hw->wiphy,
                           "%s (freq=%d(%d - %d)/%s idle=%d ps=%d
smps=%s)\n",
@@ -2650,7 +2660,9 @@ static int mac80211_hwsim_new_radio(struct genl_info
*info,
         ieee80211_hw_set(hw, AMPDU_AGGREGATION);
         ieee80211_hw_set(hw, MFP_CAPABLE);
         ieee80211_hw_set(hw, SIGNAL_DBM);
+       ieee80211_hw_set(hw, SUPPORTS_PS);
         ieee80211_hw_set(hw, TDLS_WIDER_BW);
+
         if (rctbl)
                 ieee80211_hw_set(hw, SUPPORTS_RC_TABLE);