On Thu, 2018-07-05 at 12:06 -0500, Larry Finger wrote: > On 07/05/2018 02:36 AM, Pkshih wrote: > > On Wed, 2018-07-04 at 10:33 -0500, Daniel Drake wrote: > >> On Wed, Jul 4, 2018 at 10:13 AM, Larry Finger <Larry.Finger@xxxxxxxxxxxx> wrote: > >>> We will have to agree to disagree. > >>> > >>> I have no idea what the vendors are doing that cause some motherboards to > >>> need a different aspm value. What I do know is that we have had to live with > >>> the idiocy of some vendors saving a few pennies by only including a single > >>> antenna, rather than two, and then making a problem by miscoding the EFUSE > >>> bit that indicates which connector is actually in use. As we have no means > >>> that I know about to detect which boxes have the problem, a module parameter > >>> was created, just as in this case. > >>> > >>> I agree that drivers should work "out of the box", but finite resources and > >>> lack of vendor cooperation make this a goal that may not be attainable. > >> > >> As you touched on, the ideal situation is that Realtek solve the > >> issue. Ping-Ke Shih is on CC and I am adding a few more contacts from > >> the commit log. The context is that the r8822 driver fails on several > >> platforms unless setting aspm=0 (the default is 1). > > > > It's hard to have all laptop or motherboards and all rtl8822be modules in my side, > > so what I can do is to analyze the issue when user encountered. > > > >> > >> https://gist.github.com/dsd/20c05f0c6d66ee2ef9bfbb17f93f18ba > >> https://bugzilla.kernel.org/show_bug.cgi?id=199651 > >> > >> > >> If we don't get a timely fix from Realtek though, I think there is a > >> key difference between the antenna selection headache and this one. In > >> the antenna case, there isn't a good value that you can set that will > >> work on all systems. If you change the default behaviour you will > >> solve the issue for some users while simultanously introducing the > >> problem on other systems that were previously fine. > >> > >> However in this case, it's highly likely that setting aspm=0 (off) by > >> default would work for everyone. It has the disadvantage of using a > >> bit more power, but especially with the indications that this issue > >> affects a significant number of systems, I think that having the > >> driver working out of the box everywhere is more important. The module > >> parameter can be left in place so that unaffected users that want to > >> save power can set aspm=1. > >> > > > > I think this issue may be due to L1 latency, so below patch would be > > helpful but not sure because I don't have the same laptop. > > Is there anyone can help to test? > > > > > > diff --git a/drivers/staging/rtlwifi/rtl8822be/hw.c b/drivers/staging/rtlwifi/rtl8822be/hw.c > > index 7947edb239a1..88ba5b2fea6a 100644 > > --- a/drivers/staging/rtlwifi/rtl8822be/hw.c > > +++ b/drivers/staging/rtlwifi/rtl8822be/hw.c > > @@ -803,7 +803,7 @@ static void _rtl8822be_enable_aspm_back_door(struct ieee80211_hw *hw) > > return; > > > > pci_read_config_byte(rtlpci->pdev, 0x70f, &tmp); > > - pci_write_config_byte(rtlpci->pdev, 0x70f, tmp | BIT(7)); > > + pci_write_config_byte(rtlpci->pdev, 0x70f, tmp | ASPM_L1_LATENCY << 3); > > This patch loses the BIT(7). Did you really mean to do that? > > I now agree that this is a bug. A similar problem had been found in a few boxes > with RTL8723BE or RTL8821AE cards, but that it might apply here completely > slipped through the ever larger cracks in my mind. > Yes, I remove BIT(7) intentionally, because this is defined as reserved bit in rtl8822be. For the older chips, I need to check with my colleagues. Regards, PK _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
