On 3/10/2020 3:44 PM, Kuppuswamy Sathyanarayanan wrote: > <snip> > > Please check the following spec reference (change to 4.5.1 Table 4-6) > > the OS is permitted to read or write DPC Control and Status registers of a > port while processing an Error Disconnect Recover notification from firmware > on that port. Error Disconnect Recover notification processing begins > with the > Error Disconnect Recover notify from Firmware, and *ends when the OS > releases > DPC by clearing the DPC Trigger Status bit*.Firmware can read DPC Trigger > Status bit to determine the ownership of DPC Control and Status > registers. Firmware > is not permitted to write to DPC Control and Status registers if DPC > Trigger Status is > set i.e. the link is in DPC state. *Outside of the Error Disconnect > Recover notification > processing window, the OS is not permitted to modify DPC Control or > Status registers*; > only firmware is allowed to. > > Since the EDR processing window ends with clearing DPC Trigger status > bit, OS needs to > clear DPC and AER registers before it ends. > > Austin, > > I think the order needs to be reversed in the implementation note. Agreed.
