On 11/2/20 10:27 AM, Jason Gunthorpe wrote: > On Mon, Nov 02, 2020 at 10:21:21AM -0800, Adit Ranadive wrote: >> On 11/2/20 10:02 AM, Jason Gunthorpe wrote: >>> On Mon, Nov 02, 2020 at 09:55:25AM -0800, Adit Ranadive wrote: >>>> On 10/29/20 9:16 AM, Adit Ranadive wrote: >>>>> On 10/29/20 4:57 AM, Jason Gunthorpe wrote: >>>>>> On Wed, Oct 28, 2020 at 11:19:45PM +0000, Adit Ranadive wrote: >>>>>>> The PVRDMA device still reports the active_speed in u8. >>>>>>> Lets use the ib_eth_get_speed to report the speed and >>>>>>> width. Unfortunately, phys_state gets stored as msb of >>>>>>> the new u16 active_speed. >>>>>> >>>>>> This explanation is not clear, I have no idea what this is fixing >>>>> >>>>> It seemed more clear to me in my head, I guess :). >>>>> >>>>> After commit 376ceb31ff87 changed the active_speed attribute to >>>>> u16, both the active_speed and phys_state attributes in the >>>>> pvrdma_port_attr struct are getting stored in this u16. As a >>>>> result, these show up as invalid values in ibv_devinfo. >>>>> >>>>> Our device still gives us back a u8 active_speed so both these >>>>> are getting stored in the u16. This fix I proposed simply gets >>>>> the active_speed from the netdev while the phys_state still >>>>> needs to come from the pvrdma device, i.e. the msb the of the >>>>> u16. I also removed some unused functions as a result. >>>>> >>>>> Alternatively, I could change the u8 active_width and u16 >>>>> active_speed to reserved now that we're getting the active_speed >>>>> and active_width from the ib_get_eth_speed function. >>>> >>>> Jason, did you have any comments on this or did you want me >>>> to just send v1 with an updated description? >>> >>> I still haven't figured out what this is fixing. >>> >>> Is 'struct pvrdma_port_attr' some kind of ABI? If so why isn't the fix >>> to revert the type? >> >> I can revert it but I thought that it had to a u16 based on the IBTA, no? >> Or does that not apply to device-level stuff? > > You didn't answer the question, it it ABI to some kind of FW interface > or something? > > *HOW* did two fields get overlapped onto a single u16?? The compiler > won't do this.. > It is an ABI to the device for port attributes. The device gives us back this structure for query port verb. The response from the device is memcopied into this pvrdma_port_attr structure. So both the bytes representing active_speed and phys_state from the device are copied into the single u16 in this structure.
