On 2023-12-05 15:35:19 GMT+01:00, Guenter Roeck wrote: > On 12/5/23 06:22, Aleksa Savic wrote: >> On 2023-12-03 18:36:35 GMT+01:00, Guenter Roeck wrote: >>> On Sun, Dec 03, 2023 at 01:06:48PM +0100, Aleksa Savic wrote: >>>> This driver exposes hardware sensors of the Gigabyte AORUS Waterforce >>>> all-in-one CPU liquid coolers, which communicate through a proprietary >>>> USB HID protocol. Report offsets were initially discovered in [1] and >>>> confirmed by me on a Waterforce X240 by observing the sent reports from >>>> the official software. >>>> >>>> Available sensors are pump and fan speed in RPM, as well as coolant >>>> temperature. Also available through debugfs is the firmware version. >>>> >>>> Attaching a fan is optional and allows it to be controlled from the >>>> device. If it's not connected, the fan-related sensors will report >>>> zeroes. >>>> >>>> The addressable RGB LEDs and LCD screen are not supported in this >>>> driver and should be controlled through userspace tools. >>>> >>>> [1]: https://github.com/liquidctl/liquidctl/issues/167 >>>> >>>> Signed-off-by: Aleksa Savic <savicaleksa83@xxxxxxxxx> >>>> --- > ... >>>> +static int waterforce_get_status(struct waterforce_data *priv) >>>> +{ >>>> + int ret = 0; >>>> + >>>> + if (!mutex_lock_interruptible(&priv->status_report_request_mutex)) { >>>> + if (!time_after(jiffies, priv->updated + msecs_to_jiffies(STATUS_VALIDITY))) { >>>> + /* Data is up to date */ >>>> + goto unlock_and_return; >>>> + } >>> >>> What is the point of this check ? The calling code already checks it. >>> Checking it twice, once inside and once outside the lock, seems >>> excessive. >>> >> >> If there are multiple readers here, only the first one should request the status, >> so when others enter the mutex they can exit early if the data is there. >> > > Please change the code to only check once from within the mutex. > > Guenter > Done in v3. Thanks, Aleksa
