The rtl8723bu wireless IC shows evidence of a more agressive approach to
power saving, powering down its RF side when there is no wireless
interfacing but leaving USB interfacing intact. This makes the wireless
IC more suitable for use in devices which need to keep their power use
as low as practical, such as tablets and Surface Pro type devices.
In effect this means that a full initialisation must be performed
whenever a wireless interface is brought up. It also means that
interpretations of power status from general wireless registers should
not be relied on to influence an init sequence.
The patch works by forcing a fuller initialisation and forcing it to
occur more often in code paths (such as occurs during a low level
authentication that initiates wireless interfacing).
The initialisation sequence is now more consistent with code based
directly on vendor code. For example while the vendor derived code
interprets a register as indcating a particular powered state, it does
not use this information to influence its init sequence.
Only devices that use the rtl8723bu driver are affected by this patch.
With this patch wpa_supplicant reliably and consistently connects with
an AP. Before a workaround such as executing rmmod and modprobe before
each call to wpa_supplicant worked with some distributions.
Signed-off-by: John Heenan <[email protected]>
---
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 04141e5..ab2f2ef 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -3900,7 +3900,7 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw)
* Fix 92DU-VC S3 hang with the reason is that secondary mac is not
* initialized. First MAC returns 0xea, second MAC returns 0x00
*/
- if (val8 == 0xea)
+ if (val8 == 0xea || priv->fops == &rtl8723bu_fops)
macpower = false;
else
macpower = true;
@@ -5779,6 +5779,12 @@ static int rtl8xxxu_start(struct ieee80211_hw *hw)
ret = 0;
+ if(priv->fops == &rtl8723bu_fops) {
+ ret = rtl8xxxu_init_device(hw);
+ if (ret)
+ goto error_out;
+ }
+
init_usb_anchor(&priv->rx_anchor);
init_usb_anchor(&priv->tx_anchor);
init_usb_anchor(&priv->int_anchor);
@@ -6080,9 +6086,11 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
goto exit;
}
- ret = rtl8xxxu_init_device(hw);
- if (ret)
- goto exit;
+ if(priv->fops != &rtl8723bu_fops) {
+ ret = rtl8xxxu_init_device(hw);
+ if (ret)
+ goto exit;
+ }
hw->wiphy->max_scan_ssids = 1;
hw->wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
--
2.10.1
On Tue, Nov 01, 2016 at 05:24:47PM +1000, John Heenan wrote:
> The rtl8723bu wireless IC shows evidence of a more agressive approach to
> power saving, powering down its RF side when there is no wireless
> interfacing but leaving USB interfacing intact. This makes the wireless
> IC more suitable for use in devices which need to keep their power use
> as low as practical, such as tablets and Surface Pro type devices.
>
> In effect this means that a full initialisation must be performed
> whenever a wireless interface is brought up. It also means that
> interpretations of power status from general wireless registers should
> not be relied on to influence an init sequence.
>
> The patch works by forcing a fuller initialisation and forcing it to
> occur more often in code paths (such as occurs during a low level
> authentication that initiates wireless interfacing).
>
> The initialisation sequence is now more consistent with code based
> directly on vendor code. For example while the vendor derived code
> interprets a register as indcating a particular powered state, it does
> not use this information to influence its init sequence.
>
> Only devices that use the rtl8723bu driver are affected by this patch.
>
> With this patch wpa_supplicant reliably and consistently connects with
> an AP. Before a workaround such as executing rmmod and modprobe before
> each call to wpa_supplicant worked with some distributions.
>
> Signed-off-by: John Heenan <[email protected]>
> ---
> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> index 04141e5..ab2f2ef 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> @@ -3900,7 +3900,7 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw)
> * Fix 92DU-VC S3 hang with the reason is that secondary mac is not
> * initialized. First MAC returns 0xea, second MAC returns 0x00
> */
> - if (val8 == 0xea)
> + if (val8 == 0xea || priv->fops == &rtl8723bu_fops)
> macpower = false;
> else
> macpower = true;
> @@ -5779,6 +5779,12 @@ static int rtl8xxxu_start(struct ieee80211_hw *hw)
>
> ret = 0;
>
> + if(priv->fops == &rtl8723bu_fops) {
> + ret = rtl8xxxu_init_device(hw);
> + if (ret)
> + goto error_out;
> + }
> +
> init_usb_anchor(&priv->rx_anchor);
> init_usb_anchor(&priv->tx_anchor);
> init_usb_anchor(&priv->int_anchor);
> @@ -6080,9 +6086,11 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
> goto exit;
> }
>
> - ret = rtl8xxxu_init_device(hw);
> - if (ret)
> - goto exit;
> + if(priv->fops != &rtl8723bu_fops) {
> + ret = rtl8xxxu_init_device(hw);
> + if (ret)
> + goto exit;
> + }
>
> hw->wiphy->max_scan_ssids = 1;
> hw->wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
> --
> 2.10.1
>
I've been trying similar modifications, testing them with the 8192eu and cu.
Basically I moved all the usb stuff out of start and stop and into probe and
disconnect. I moved the call to rtl8xxxu_init_device() from probe to
start.
Doing wpa_supplicant restart tests, the 8192cu still works everytime as it did
before. The 8192eu now works at least 50% of the time, and when it fails it's
now during the 4-way handshake phase which may be a separate issue confined to
the 8192eu only.
Note these results rely on changing the macpower test to this -
if(val8 == 0xea || val8 == 0xff)
which is different again from what you are using so I'm of the opinion we
need to come up with a different way of telling whether the mac is powered.
John Heenan <[email protected]> writes:
> The rtl8723bu wireless IC shows evidence of a more agressive approach to
> power saving, powering down its RF side when there is no wireless
> interfacing but leaving USB interfacing intact. This makes the wireless
> IC more suitable for use in devices which need to keep their power use
> as low as practical, such as tablets and Surface Pro type devices.
>
> In effect this means that a full initialisation must be performed
> whenever a wireless interface is brought up. It also means that
> interpretations of power status from general wireless registers should
> not be relied on to influence an init sequence.
>
> The patch works by forcing a fuller initialisation and forcing it to
> occur more often in code paths (such as occurs during a low level
> authentication that initiates wireless interfacing).
>
> The initialisation sequence is now more consistent with code based
> directly on vendor code. For example while the vendor derived code
> interprets a register as indcating a particular powered state, it does
> not use this information to influence its init sequence.
>
> Only devices that use the rtl8723bu driver are affected by this patch.
>
> With this patch wpa_supplicant reliably and consistently connects with
> an AP. Before a workaround such as executing rmmod and modprobe before
> each call to wpa_supplicant worked with some distributions.
>
> Signed-off-by: John Heenan <[email protected]>
> ---
> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
I am at Linux Plumbers this week, so my response time is slow. Next week
I am on PTO, so I will not respond.
First of all, why do you keep CC'ing multiple mailing lists that do not
matter? This discussion belongs on linux-wireless not on netdev or lkml.
CC'ing Kalle directly is not going to get him to apply this broken patch
for you.
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> index 04141e5..ab2f2ef 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> @@ -3900,7 +3900,7 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw)
> * Fix 92DU-VC S3 hang with the reason is that secondary mac is not
> * initialized. First MAC returns 0xea, second MAC returns 0x00
> */
> - if (val8 == 0xea)
> + if (val8 == 0xea || priv->fops == &rtl8723bu_fops)
> macpower = false;
> else
> macpower = true;
Why oh why do you insist on not using the *standard* way of coping with
this? 'priv-rtl_chip' is used everywhere else, but you just have to do
something awful like this?
> @@ -5779,6 +5779,12 @@ static int rtl8xxxu_start(struct ieee80211_hw *hw)
>
> ret = 0;
>
> + if(priv->fops == &rtl8723bu_fops) {
> + ret = rtl8xxxu_init_device(hw);
> + if (ret)
> + goto error_out;
> + }
> +
> init_usb_anchor(&priv->rx_anchor);
> init_usb_anchor(&priv->tx_anchor);
> init_usb_anchor(&priv->int_anchor);
Read Documentation/CodingStyle - as others already pointed you at.
> @@ -6080,9 +6086,11 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
> goto exit;
> }
>
> - ret = rtl8xxxu_init_device(hw);
> - if (ret)
> - goto exit;
> + if(priv->fops != &rtl8723bu_fops) {
> + ret = rtl8xxxu_init_device(hw);
> + if (ret)
> + goto exit;
> + }
>
> hw->wiphy->max_scan_ssids = 1;
> hw->wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
Again coding style violation.
Second, I am NOT going to accept any patches that fundamentally changes
the init sequence of the code for just one device.
I already told you I want to find out *why* this matters, and what part
of rtl8xxxu_init_device() is the culprit. I want to understand the
actual problem, not just blindly move stuff around.
Jes
On 1 November 2016 at 08:24, John Heenan <[email protected]> wrote:
> @@ -5779,6 +5779,12 @@ static int rtl8xxxu_start(struct ieee80211_hw *hw)
>
> ret =3D 0;
>
> + if(priv->fops =3D=3D &rtl8723bu_fops) {
OK, let me be the first. Documentation/CodingStyle also says to use
space between "if" and "(" ;)
> @@ -6080,9 +6086,11 @@ static int rtl8xxxu_probe(struct usb_interface *in=
terface,
> goto exit;
> }
>
> - ret =3D rtl8xxxu_init_device(hw);
> - if (ret)
> - goto exit;
> + if(priv->fops !=3D &rtl8723bu_fops) {
Same here.
I reviewed style only.
--=20
Rafa=C5=82