On Fri, Sep 18, 2020 at 07:43:15PM +0200, Marek Behun wrote: > On Fri, 18 Sep 2020 15:42:01 +0200 > Simon Guinot <simon.guinot@xxxxxxxxxxxx> wrote: > > > On Fri, Sep 18, 2020 at 12:52:58AM +0200, Marek Behun wrote: > > > Hi, > > > > Hi Marek, > > > > > > > > the leds-ns2 kernel driver has allows 3 modes for a LED: > > > OFF, ON and blinking on SATA activity > > > > > > This third mode is activated via another sysfs file in the LED device > > > sysfs directory: /sys/class/leds/<LED>/sata. > > > > > > Since we now support LED private HW triggers, it would be better if > > > this was rewritten to use this new API. > > > > It sounds like a great idea. > > > > > > > > The question is how many people use this mode and may complain if we > > > change this sysfs ABI? > > > > Not a lot IMHO. This LED devices are found in some LaCie/Seagate NAS. > > Most of them, such as the Seagate NAS 4-Bay (Marvell Armada 370 SoC) > > are supported by the Debian distribution. For the users I have been in > > contact with, I am pretty confident they should be able to deal with > > this changes. They already dealt with worse. > > > > Another user is the Seagate NAS distribution. And this user will be > > happy to switch to the new ABI. > > > > > > > > Another question is whether the LED supports another HW blinking mode, > > > or just SATA? How is this wired on the board? > > > > Three different LED modes are available: off, on and SATA activity > > blinking. The LED modes are controlled through two GPIOs (command and > > slow): each combination of values for the command/slow GPIOs corresponds > > to a LED mode. > > > > For an example, have a look at the leds-ns2 DT node in the > > armada-370-seagate-nas-4bay.dts file. > > > > The only hardware blinking mechanism for this LED device is SATA. > > Basically the SATA blinking signal is built from the SATA pin activity > > of the HDD. This signal is a little bit reworked by some electronic > > components in order to produce a blinking rate OK for the human eye. > > > > Hope this helps. > > > > Simon > > I apologize, I accidentaly sent the question from my private e-mail :) > > Simon, thanks for the info. > > Another question: Is there only one disk on this device? There are several NAS devices using the leds-ns2 driver. On most of them the activity is wired to a single disk. But on some (such as the Network Space v2 Max), the activity is wired to two disks. > > The reason why I am asking is this: > We already have disk-activity trigger. I would like to implement a > generic LED trigger offloading API, so that if user chooses > disk-activity and the LED can offload that to hardware, it wil. > > But the disk-activity trigger blinks the LED on activity of any > disk, you can't choose one as in the netdev trigger. > > If it is possible to have only one disk on that device (which is > improbable if there are USB ports) than implementing offloading will > be trivial. > > If not, than we would need to allow disk-activity trigger to select > the disk as well. This is probably good anyway. > > Are you willing to work on this with me? At least reviewing and testing > patches? Yes I'll review and test your patches. Simon
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