> -----Original Message----- > From: Mika Westerberg [mailto:[email protected]] > Sent: Sunday, May 21, 2017 13:47 > To: Bernat, Yehezkel <[email protected]> > Cc: Levy, Amir (Jer) <[email protected]>; Lukas Wunner > <[email protected]>; Greg Kroah-Hartman <[email protected]>; > Andreas Noever <[email protected]>; Jamet, Michael > <[email protected]>; Andy Lutomirski <[email protected]>; > [email protected]; [email protected]; Andy Shevchenko > <[email protected]>; [email protected] > Subject: Re: [PATCH 18/24] thunderbolt: Store Thunderbolt generation in the > switch structure > > On Sun, May 21, 2017 at 09:55:55AM +0000, Bernat, Yehezkel wrote: > > > > > > > -----Original Message----- > > > From: Levy, Amir (Jer) > > > Sent: Sunday, May 21, 2017 11:07 > > > To: Mika Westerberg <[email protected]>; Lukas Wunner > > > <[email protected]> > > > Cc: Greg Kroah-Hartman <[email protected]>; Andreas > Noever > > > <[email protected]>; Jamet, Michael > > > <[email protected]>; Bernat, Yehezkel > > > <[email protected]>; Andy Lutomirski <[email protected]>; > > > [email protected]; [email protected]; Andy > > > Shevchenko <[email protected]>; > > > [email protected] > > > Subject: RE: [PATCH 18/24] thunderbolt: Store Thunderbolt generation > > > in the switch structure > > > > > > On Sun, May 21 2017, 11:00 AM, Mika Westerberg wrote: > > > > On Sun, May 21, 2017 at 10:40:41AM +0300, Mika Westerberg wrote: > > > > > On Sun, May 21, 2017 at 07:35:21AM +0200, Lukas Wunner wrote: > > > > > > On Sun, May 21, 2017 at 05:29:47AM +0000, Levy, Amir (Jer) wrote: > > > > > > > On Sun, May 21 2017, 07:47 AM, Lukas Wunner wrote: > > > > > > > > On Thu, May 18, 2017 at 05:39:08PM +0300, Mika Westerberg > wrote: > > > > > > > > > + > > > > > > > > > + default: > > > > > > > > > + sw->generation = 1; > > > > > > > > > + break; > > > > > > > > > > > > > > > > If someone adds an entry for, say, a new TB3 controller to > > > > > > > > nhi_ids[] but forgets to update this function, the > > > > > > > > controller is assigned the wrong generation number. It > > > > > > > > might be better to make TB3 the default and list each TB1 > > > > > > > > controller instead since it's less likely for Intel to > > > > > > > > introduce an > older gen chip. > > > > > > > > > > > > > > > > Generally I think it's problematic to require that > > > > > > > > multiple files are touched whenever a new controller is > > > > > > > > added. Isn't the generation number or link speed > > > > > > > > (10/20/40) stored in some register in PCI config space (VSEC > 0x1234) or TB config space? > > > > > > > > > > > > > > How about setting information, that isn't available from > > > > > > > PCI, in pci_device_id.driver_data when initializing nhi_ids[]? > > > > > > > > > > > > Right, that would also be possible, though reading the > > > > > > generation number from a register would be more elegant, if such a > register exists. > > > > > > > > > > I don't think there is such register but I can put this > > > > > information to the driver_data instead. > > > > > > > > Actually these are Thunderbolt switch IDs, not NHI PCI IDs so I > > > > don't think driver_data is the right place after all. So if no > > > > objections, I'll update the function to default to TBT3 but keep > > > > the switch case and add the TBT1 IDs + Win Ridge there. > > > > > > There is correlation between switch ID to NHI ID. > > > > I'm not sure defaulting to TBT3 is a good idea. ICM message format can > > be changed, DMA port can be different, nothing guaranties correct > > operation of the driver with newer unknown controllers. > > Fair enough :) Then we just need to remember to update the function here > as new generations get added and tested. > > I suppose you don't know either if we could use the revision or similar field > in > the switch config space to determine generation somehow?
Nothing that I'm aware of. Still, I like the idea of having a table-like construct somewhere in the code to centralize the handling of various controller-specific info (generation, DMA port, maybe more things in the future).
