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Lifebook E734/E744/E754 has a LED which the manual calls "radio components indicator". It should be lit when any radio transmitter is enabled. Its state can be read and set using ACPI (FUNC interface, RFKILL method). Since the Lifebook E734/E744/E754 only has a button (as compared to a slider) for enabling/disabling radio transmitters, I believe the LED in question is meant to indicate whether all radio transmitters are currently on or off. However, pressing the radio toggle button does not automatically change the hardware state of the transmitters: it looks like this machine relies on soft rfkill. As for detecting whether the LED is present on a given machine, I had to resort to educated guesswork. I assumed this LED is present on all devices which have a radio toggle button instead of a slider. My Lifebook E744 holds 0x01010001 in BTNI. By comparing the bits and buttons with those of a Lifebook E8420 (BTNI=0x000F0101, has a slider), I put my money on bit 24 as the indicator of the radio toggle button being present. Furthermore, bit 24 is also clear on the S7020 which does not have the toggle button or an RF LED. Figuring out how the LED is controlled was more deterministic as all it took was decompiling the DSDT and taking a look at method S000 (the RFKILL method of the FUNC interface). The LED control method implemented here is unsuitable for use with "heavy" LED triggers, like phy0rx. Once blinking frequency achieves a certain level, the system hangs. Signed-off-by: Michał Kępień <kernel@kempniu.pl> [jwoithe: Comment on bit 24 in BTNI, expanded commit msg] Signed-off-by: Jonathan Woithe <jwoithe@just42.net> [dvhart: Minor style and commit log adjustments] Signed-off-by: Darren Hart <dvhart@linux.intel.com> |
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