From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: Re: [PATCH 2/2] serial: 8250: Add support for 8250/16550 as MFD function Date: Tue, 21 May 2019 16:43:19 +0200 Message-ID: <20190521144319.GA28747@kroah.com> References: <87bm05mpmx.fsf@haabendal.dk> <20190514104741.GO4319@dell> <20190514122618.GA18859@kroah.com> <87imudky2o.fsf@haabendal.dk> <20190521100904.GA13612@kroah.com> <87pnocm59v.fsf@haabendal.dk> <20190521111817.GA24911@kroah.com> <87lfz0m3ge.fsf@haabendal.dk> <20190521125651.GA6264@kroah.com> <87h89nnajr.fsf@haabendal.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <87h89nnajr.fsf@haabendal.dk> Sender: linux-kernel-owner@vger.kernel.org To: Esben Haabendal Cc: Lee Jones , linux-serial@vger.kernel.org, Jiri Slaby , Nishanth Menon , Vignesh R , Tony Lindgren , Lokesh Vutla , Florian Fainelli , linux-kernel@vger.kernel.org List-Id: linux-serial@vger.kernel.org On Tue, May 21, 2019 at 04:31:52PM +0200, Esben Haabendal wrote: > Greg Kroah-Hartman writes: > > > On Tue, May 21, 2019 at 01:50:25PM +0200, Esben Haabendal wrote: > >> Greg Kroah-Hartman writes: > >> > >> > On Tue, May 21, 2019 at 01:11:08PM +0200, Esben Haabendal wrote: > >> >> Greg Kroah-Hartman writes: > >> >> > >> >> >> I will try ad hold back with this thread until you get back to it. > >> >> > > >> >> > Ok, I have no idea what is going on here, sorry. This is a really long > >> >> > and meandering thread, and I can't even find the original patches in my > >> >> > queue. > >> >> > > >> >> > So can you resend things and we can start over? :) > >> >> > >> >> Will do. > >> >> > >> >> > But note, using a mfd for a uart seems VERY odd to me... > >> >> > >> >> Ok. In my case, I have a pcie card with an fpga which includes 5 uart > >> >> ports, 3 ethernet interfaces and a number of custom IP blocks. > >> >> I believe that an mfd driver for that pcie card in that case. > >> > > >> > I believe you need to fix that fpga to expose individual pci devices > >> > such that you can properly bind the individual devices to the expected > >> > drivers :) > >> > >> Well, that is really out-of-scope of what I am doing here. > > > > Not really, if you have control over the fpga firmware (and odds are you > > do), just fix that and instantly your device works with all kernels, no > > need to change anything. > > > > Why not do this? > > Because I do not have control over fpga firmware. Who does? Why did they create it this way if it can not be accessed by an operating system as-is? Has it passed the PCI tests? Do you have a link to where you can get this crazy device? > >> > Seriously, who makes such a broken fpga device that goes against the PCI > >> > spec that way? Well, not so much as "goes against it", as "ignores all > >> > of the proper ideas of the past 20 years for working with PCI devices". > >> > >> Might be. But that is the firmware I have to work with here, and I > >> still hope we can find a good solution for implementing a driver without > >> having to maintain out-of-tree patches. > > > > As this hardware will not work on any operating system as-is, why not > > fix the firmware to keep from having to support a one-off device that no > > one else would be crazy enough to create? :) > > Clearly, someone has been crazy enough. Hopefully, we can be smart > enough to make Linux fit to it. Sometimes you need to go tell the hardware/firmware people not to do foolish things. You can not always fix their problems in software. Please push back on this. thanks, greg k-h