On Wed, 2016-05-04 at 13:03 +0300, Andy Shevchenko wrote: > On Wed, May 4, 2016 at 12:51 PM, Bryan O'Donoghue > <pure.logic@xxxxxxxxxxxxxxxxx> wrote: > > On Wed, 2016-05-04 at 12:42 +0300, Andy Shevchenko wrote: > > > On Wed, May 4, 2016 at 12:31 PM, Bryan O'Donoghue > > > <pure.logic@xxxxxxxxxxxxxxxxx> wrote: > > > > Andy, > > > > > > > > If you are going to start removing working PCI devices from the > > > > PCI > > > > config table in favour of a shim in SERIAL_8250_LPSS then the > > > > very > > > > minimum should be some sort of dependency link between > > > > SERIAL_8250_LPSS > > > > and CONFIG_SERIAL_8250_PCI in kconfig. > > > > > > > > A user could reasonably read the QRK datasheet - switch on > > > > CONFIG_SERIAL_8250_PCI and then wonder why no console output > > > > happened > > > > on boot. S/he shouldn't have to know that devices were moved > > > > from > > > > the > > > > PCI driver to an LPSS shim driver or that the 8250_lpss driver > > > > now > > > > needs to be selected instead of the intuitively correct > > > > 8250_pci > > > > driver. > > > > > > That is taken care of since default is set to SERIAL_8250 (you > > > even > > > don't need to have PCI driver enabled!). > > > Doesn't work for you? > > > > The default may be set to SERIAL_8250 but, without the QRK specific > > entry in 8250_pci.c you won't get console output. > > > > So if you are going to remove the QRK entry from 8250_pci.c and > > stuff > > it into 8250_lpss.c then 8250_lpss needs to be selected by > > CONFIG_SERIAL_8250_PCI. > > Why?! > > Now it should be enough to have SERIAL_8250 set to non-n to have > 8250_lpss compiled. > Can you check it? I'm sure that's true. My point to you is that - its a highly non-intuitive thing to do on a reading of the datasheet for this part. LPSS is, ostensibly at least, for passing processor resources via APCI. If you look at a QRK datasheet it says "enumerate all this stuff via PCI" - there's not a single mention of LPSS. Its reasonable, correct and currently required for QRK to set CONFIG_8250_PCI. To move away from a valid/standard PCI probe routine into a new special LPSS/PCI shim (which the hardware doesn't actually mandate) I do think you should to setup the dependency CONFIG_8250_PCI => CONFIG_8250_LPSS. --- bod -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
