On Do, 2019-01-03 at 02:10 +0100, Marek Vasut wrote: > The information whether the SMSC95xx is in_pm or not can be derived from > the usbdev->suspend_count. First thing called in smsc95xx_suspend() is > usbnet_suspend(), which increments the usbdev->suspend_count and since > then the driver only calls _nopm() functions and functions with in_pm > set to 1. The smsc95xx_resume() does the inverse, it calls functions > with _nopm() suffix and with in_pm set to 1 until usbnet_resume(), which > sets the usbdev->suspend_count to 0. Hi, unfortunately I am forced to disagree in the strongest terms. The logic behind this patch is wrong. The "in_pm" parameter exists because some function need to be called in the code paths needed to implement power management. Under those circumstances they must not take a pm reference to keep the device awake, lest the driver deadlock. (For example __smsc95xx_read_reg) However from other code paths precisely that reference must be taken in order to make sure that the driver do not try to communicate with a suspended device. If you check the suspend counter, you will omit the necessary getting of a reference precisely when it is needed. The driver will never dedalock, but you will cause numerous races. I must suggest to simply drop this part and redo the series. Regards Oliver
