From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH v3 09/11] serial: 8250_lpss: move Quark code from PCI driver Date: Wed, 04 May 2016 14:20:35 +0300 Message-ID: <1462360835.17131.224.camel@linux.intel.com> References: <1461764894-14891-1-git-send-email-andriy.shevchenko@linux.intel.com> <1461764894-14891-10-git-send-email-andriy.shevchenko@linux.intel.com> <1462354262.27858.153.camel@nexus-software.ie> <1462355477.27858.161.camel@nexus-software.ie> <1462359696.27858.184.camel@nexus-software.ie> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1462359696.27858.184.camel@nexus-software.ie> Sender: linux-kernel-owner@vger.kernel.org To: Bryan O'Donoghue , Andy Shevchenko Cc: Peter Hurley , "linux-serial@vger.kernel.org" , Vinod Koul , "linux-kernel@vger.kernel.org" , dmaengine , Greg Kroah-Hartman , "Puustinen, Ismo" , Heikki Krogerus List-Id: linux-serial@vger.kernel.org On Wed, 2016-05-04 at 12:01 +0100, Bryan O'Donoghue wrote: > On Wed, 2016-05-04 at 13:03 +0300, Andy Shevchenko wrote: > > > > On Wed, May 4, 2016 at 12:51 PM, Bryan O'Donoghue > > wrote: > > > > > > The default may be set to SERIAL_8250 but, without the QRK > > > specific > > > entry in 8250_pci.c you won't get console output. That's, by the way, not true. > > > > > > 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. User has no such item even visible until enable CONFIG_EXPERT. Heikki sent an answer to you (and to the list, but by some reason it's not yet there) an hour ago. > > 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. No, this is what we try avoiding, thus it will not happen. If user selects CONFIG_SERIAL_8250_PCI, the CONFIG_SERIAL_8250_LPSS will be selected as well since it has same dependencies. -- Andy Shevchenko Intel Finland Oy