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Date: Fri, 24 Apr 2015 15:39:15 +0800 From: Alex Hung <alex.hung@...onical.com> To: Pali Rohár <pali.rohar@...il.com> Cc: Gabriele Mazzotta <gabriele.mzt@...il.com>, Darren Hart <dvhart@...radead.org>, Matthew Garrett <mjg59@...f.ucam.org>, "platform-driver-x86@...r.kernel.org" <platform-driver-x86@...r.kernel.org>, linux-kernel@...r.kernel.org Subject: Re: [PATCH 0/3] Dell Airplane Mode Switch driver I encountered a Dell Latitude machine whose wireless hotkey will not work with dell-rbtn alone, and therefore I merged functions from dell-wireless and it worked quite well. I also tested it on 7 other Dell machines, and only Inspiron 7437 failed because of a firmware bug (see http://permalink.gmane.org/gmane.linux.acpi.devel/74915) I am going to send the new patch for review. On Fri, Dec 26, 2014 at 4:11 AM, Pali Rohár <pali.rohar@...il.com> wrote: > I will try to recap all information which we have... > > *) We should not send wireless key press to userspace when BIOS > already handles wireless state (and enable/disable wifi): > http://www.spinics.net/lists/platform-driver-x86/msg05922.html > > *) some tested dell machines does not implement GRBT method (or > report constant value) which could return state of wireless > (enabled/disabled) -- e.g. Inspiron 7447 > > *) dell-wireless driver is doing nothing on devices which have > wireless slider switch (except calling CRBT/ARBT methods) > > *) all tested machines emit key with keycode 240 (scancode is > probably 136 = 0x88) to userspace via i8042 bus/AT keyboard when > wireless button/slider is pressed/switched > > *) both drivers dell-wireless and dell-rbtn do not implement > setting soft rfkill state (or change wifi state) > > So in my opinion: if we decide to use driver for acpi DELLABCE > device we should use dell-rbnt for devices with hw slider switch > and dell-wireless for devices with fn button. I think it does not > make sense to use dell-wireless for devices with hw slider > because it do nothing and dell-rbtn for devices with fn key > button as GRBT does not working properly. > > And second note: Do we need some driver for acpi DELLABCE device? > Which problem is trying acpi DELLABCE device to solve? Is not > everything working fine without driver for DELLABCE device? > > My dell-rbtn approach is trying to export rfkill interface from > DELLABCE device and eliminate using i8042 hook function in smbios > dell-laptop driver. > > Alex, can you check if scancode of wireless change generated by > BIOS is on all machines same: 136 (0x88)? And is send by keyboard > controller (not acpi/wmi)? > > On Thursday 25 December 2014 04:13:02 Alex Hung wrote: >> I usually prefer to stick with formal document as everything >> else can be changed without reasons. >> >> I am not certain whether the keypress is defined in Dell's >> document, and I will confirm with Dell. If this keypress is >> well defined, it is a good idea to use it. >> >> >> On Wed, Dec 24, 2014 at 7:40 PM, Gabriele Mazzotta >> >> <gabriele.mzt@...il.com> wrote: >> > On Wednesday 24 December 2014 17:13:45 Alex Hung wrote: >> >> I uploaded acpidump files [1] (except for XPS 13 which is >> >> not available), and this should help clarify what has been >> >> tested. >> >> >> >> Does Inspirion 5721 does not have either DELLABCE or >> >> DELRBTN. It is used for comparison. My apologies that I >> >> did not point this out in previous email. >> >> >> >> When calling ARBT(1), BIOS will no longer issue scancode >> >> and will not pull low hardware pin "W_DISABLE#" on mini >> >> card. This essentially gives all wireless control to OS. >> >> This is likely the answer to Microsoft's Windows >> >> Certification Program >> >> System.Client.RadioManagement.HardwareButton [2] as below: >> >> >> >> ============================================= >> >> If a PC has a physical (hardware) button switch on a PC >> >> that turns wireless radios on and off, it must be software >> >> controllable and interact appropriately with the Radio >> >> Management UI >> >> ============================================= >> >> >> >> Dell's BIOS does issue a notify(RBTN, 0x80). This is done >> >> purposely to re-enumerate the state of radio switch which >> >> may be changed when system is in S3 or S4. I think this >> >> should not occur when CRBT returns 0 or 1 (for hotkey that >> >> cannot be changed during S3 or S4), but that's how it is >> >> done currently. >> > >> > The notification is sent on my XPS13 (CRBT returns 0), >> > toggling the WiFi state on resume. >> > >> >> dell-wireless does not handle this notification in S3 or S4 >> >> for following reasons: >> >> >> >> 1. dell-wireless does not handle slider (i.e. CRBT = 2 or >> >> 3). Device drivers should read the hardware pin, >> >> "W_DISABLE#" on mini spec and change hard block >> >> accordingly. This pin is commonly used by OEM today. >> >> >> >> 2. it is not possible to distinguish the notification >> >> (0x80) from hotkey press or S3/S4. I also concerned this >> >> may mis-trigger state change when resuming from S3 or S4, >> >> but it does not. Does any know how to ignore this >> >> notification during resume only? >> >> >> >> dell-rbtn can use this notification + method (GRBT) [2] to >> >> solve the problem that slider state. >> > >> > Unfortunately this won't solve the problem for me. After >> > ARBT is called with 1 as parameter, it seems that GRBT >> > always returns 1. >> > >> > I don't know how to ignore the notification on resume, if >> > not through a flag set by a PM callback. >> > >> > Given that all the tested laptops reported a keypress on the >> > i8042 bus, isn't it better to rely on that instead? >> > >> >> [1] http://people.canonical.com/~alexhung/dell-acpidump/ >> >> [2] >> >> http://msdn.microsoft.com/en-us/library/windows/hardware/j >> >> j128256.aspx [3] It seems GRBT may not always be >> >> implemented... >> >> >> >> I'd love to do more tests and share the results on any >> >> particular systems, but I may need some more detailed >> >> instructions. >> >> >> >> >> >> >> >> On Tue, Dec 23, 2014 at 3:16 AM, Gabriele Mazzotta >> >> >> >> <gabriele.mzt@...il.com> wrote: >> >> > On Monday 22 December 2014 15:27:57 Alex Hung wrote: >> >> >> = Testing = >> >> >> >> >> >> I tested six Dell systems for two sets of patches for >> >> >> dell radio button - two system with radio slider and >> >> >> four with radio hotkey. There are also two systems with >> >> >> working ARBT method. >> >> >> >> >> >> == Basic Information == >> >> >> Based OS: Ubuntu 14.10 (kernel 3.16 [1]) and kernel 3.18 >> >> >> [2] >> >> >> >> >> >> Patches: >> >> >> 1. dell-wireless v3 = original v2 + Gabriele's >> >> >> suggestion [3] 2. dell-rbtn [4] >> >> >> >> >> >> Method: >> >> >> 1. run "rfkill list" and press hotkey / toggle slider >> >> >> during runtime 2. run "rfkill list" and toggle slider >> >> >> during S3 >> >> >> >> >> >> == Results == >> >> >> >> >> >> I summarized the tests in Google sheet as below. Please >> >> >> advise if anyone has problem reading it. >> >> >> >> >> >> https://docs.google.com/spreadsheets/d/1voffS6dNglwAExSG >> >> >> h3UmG__UAO2qfZ829CkJLPo06aI/edit?usp=sharing >> >> >> >> >> >> PS. The document will stay as long as possible for >> >> >> future references. >> >> >> >> >> >> == Summary == >> >> >> >> >> >> 1. I did not observed a duplicated event. However, >> >> >> keycode 240 (unknown) is generated on many UUT. It is >> >> >> not issued by dell-laptop or del-wmi. I am suspecting >> >> >> it is the other event Pali observes but it can be the >> >> >> result of different distro. >> >> >> >> >> >> 2. Some system issues scancode "0xe0 0x73 0xe0 0xf3". It >> >> >> can also be used toggle wireless state but this can >> >> >> also be distro-dependent. This scancode does nothing on >> >> >> Ubuntu 14.10. >> >> >> >> >> >> 2. There are two systems with working ARBT (XPS 13 9333 >> >> >> and Inspiron 7447). Calling ARBT(1) changes BIOS >> >> >> behaviours, and this matches to Dell's document. We >> >> >> should include it in the patch for maximum capability. >> >> >> >> >> >> >> >> >> [1] dell-wireless is only tested 3.16. >> >> >> [2] dell-rbtn is tested on 3.16 and 3.18, but no >> >> >> differences are observed. [3] >> >> >> http://people.canonical.com/~alexhung/dell-wireless/ >> >> >> [4] http://people.canonical.com/~alexhung/dell-rbtn/ >> >> > >> >> > I've just tried the last revision of dell-wireless and >> >> > noticed that a notification (0x80) is sent to DELLABCE >> >> > after a transition from S3 to S0, causing dell-wireless >> >> > to send KEY_RFKILL. This shouldn't happen. Same thing >> >> > for transitions from S4 to S0. >> >> > >> >> > Gabriele > > -- > Pali Rohár > pali.rohar@...il.com -- Cheers, Alex Hung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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