Re: [PATCH 0/4] ntb: idt: Add hwmon temperature sensor interface

From: Jon Mason
Date: Wed Oct 31 2018 - 17:27:28 EST


On Sat, Jul 14, 2018 at 02:58:30PM +0300, Serge Semin wrote:
> IDT PCIe-switches are equipped with an embedded temperature sensor. It
> works within the range [0; 127.5]C with a resolution of 0.5C. It can
> be used to monitor the chip core temperature so to have prevent it from
> possible overheating. It might be very topical for the chip, since it
> gets heated like in hell especially if ASPM isn't enabled.
>
> Other than the current sampled temperatur, the sensor interface exposes
> history registors with lowest and highest measured temperature, thresholds
> and alarm IRQs enabled/disable bits, ADC/filter settings. The device manual
> states that the switch is able to generate a msi interrupt on PCIe upstreams
> if the temperature crosses one of three configurable thresholds. But in
> practice we discovered that the enable/disable threshold IRQs bits interface
> is very broken (see the third patch commit message), so it can't be used
> to create the hwmon alarm interface. As the result we had to remove the
> already available temperature sensor IRQ handler and disable the corresponding
> interrupt.
>
> Current version of the driver provides following standard hwmon sysfs
> files: temperature input, lowest and highest measured temperature
> with possibility to reset the history, temperature offset. The rest of the
> nodes can't be safely implemented for the chip due to the described issues.
>
> Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>

FYI, I'm waiting on you to correct the kbuild issues. I have been
assuming you knew this, but given the lack of follow-up patches I am
beginning to this you might believe I'm ignoring them. I'm not :)

Thanks,
Jon

>
> Serge Semin (4):
> ntb: idt: Alter temperature read method
> ntb: idt: Add basic hwmon sysfs interface
> ntb: idt: Discard temperature sensor IRQ handler
> ntb: idt: Alter the driver info comments
>
> drivers/ntb/hw/idt/Kconfig | 4 +-
> drivers/ntb/hw/idt/ntb_hw_idt.c | 317 ++++++++++++++++++++++++++++++++++------
> drivers/ntb/hw/idt/ntb_hw_idt.h | 87 ++++++++++-
> 3 files changed, 353 insertions(+), 55 deletions(-)
>
> --
> 2.12.0
>