From mboxrd@z Thu Jan 1 00:00:00 1970 From: ezequiel.garcia@free-electrons.com (Ezequiel Garcia) Date: Tue, 18 Jun 2013 18:40:50 -0300 Subject: [PATCH v3 11/12] ARM: mvebu: Relocate Armada 370 PCIe device tree nodes In-Reply-To: <201306182320.07351.arnd@arndb.de> References: <1371554737-25319-1-git-send-email-ezequiel.garcia@free-electrons.com> <201306182022.08927.arnd@arndb.de> <20130618190223.GA6578@obsidianresearch.com> <201306182320.07351.arnd@arndb.de> Message-ID: <20130618214049.GA15234@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jun 18, 2013 at 11:20:07PM +0200, Arnd Bergmann wrote: > On Tuesday 18 June 2013, Jason Gunthorpe wrote: > > On Tue, Jun 18, 2013 at 08:22:08PM +0200, Arnd Bergmann wrote: > > > > > > > > Arnd, we've discussed this at length with you while getting the PCIe > > > > > > driver merged, and we've explained this to you numerous times. Could > > > > > > you please understand that any of your proposal that suggests writing > > > > > > down static windows for PCIe devices will not work? > > > > > > > > > > Where did I suggest static windows for PCIe devices? > > > > > > > > Where does your new proposal buys us anything useful compared to the > > > > existing PCIe DT binding that has been discussed at length with you? > > > > > > I'm pretty sure I explained the idea above originally and was ignored. > > > Jason Gunthorpe might remember better, but I think he liked it when I > > > originally proposed doing it this way. > > > > I remember it took a bit to understand your proposal, but I thought it > > could work, but I admit I forget all the little details now :( > > > > Ah, if I can just rephrase simply - the notion was to move the > > determination of the aperture to use dynmic allocation and then > > restructure the ranges around the mbus target, since they no longer > > need to encode the aperture. > > Right. > > > My concern: dynamically sizing the aperture is hard. There are three > > apertures that need to be picked, and the PCI core code has no support > > for dynamic apertures. Getting the aperture from the DT is a > > functional compromise. > > After some discussion on IRC with Ezequiel, I think it's best to leave > the aperture listed in DT but say in the binding that the OS may > override it. > Yes, I'll send a v4 soon, and I'll try to address this correctly, as you're suggesting. [...] > > IMHO, I go back to my original thoughts. There is no real need for any > > of this to be dynamic, we can use the values in the DT, presumably set > > by the bootloader and things will work well. > > > > The added complexity and failure modes for dynamic is simply not worth > > it.. > > I don't think it's too hard to be prepared for fully dynamic operation. > As Grant said in his comment on v2, the real complexity comes from the > fact that we are mixing dynamic and static configuration here, and > the PCIe configuration is inherently dynamic. > > The change I'm proposing would just mean the DT representation reflects > the dynamic nature of the PCIe windows. > Although I'd like the binding to take this into account, for there's no point in restricting it -a priori- I can't see *any* advantage on doing fully dynamic window configuration on devices that are fixed in the first place. It sounds like bloating the whole thing without a strong need. -- Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ezequiel Garcia Subject: Re: [PATCH v3 11/12] ARM: mvebu: Relocate Armada 370 PCIe device tree nodes Date: Tue, 18 Jun 2013 18:40:50 -0300 Message-ID: <20130618214049.GA15234@localhost> References: <1371554737-25319-1-git-send-email-ezequiel.garcia@free-electrons.com> <201306182022.08927.arnd@arndb.de> <20130618190223.GA6578@obsidianresearch.com> <201306182320.07351.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <201306182320.07351.arnd-r2nGTMty4D4@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Arnd Bergmann Cc: Andrew Lunn , Jason Cooper , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Jason Gunthorpe , Maen Suleiman , Lior Amsalem , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Sebastian Hesselbarth List-Id: devicetree@vger.kernel.org T24gVHVlLCBKdW4gMTgsIDIwMTMgYXQgMTE6MjA6MDdQTSArMDIwMCwgQXJuZCBCZXJnbWFubiB3 cm90ZToKPiBPbiBUdWVzZGF5IDE4IEp1bmUgMjAxMywgSmFzb24gR3VudGhvcnBlIHdyb3RlOgo+ ID4gT24gVHVlLCBKdW4gMTgsIDIwMTMgYXQgMDg6MjI6MDhQTSArMDIwMCwgQXJuZCBCZXJnbWFu biB3cm90ZToKPiA+IAo+ID4gPiA+ID4gPiBBcm5kLCB3ZSd2ZSBkaXNjdXNzZWQgdGhpcyBhdCBs ZW5ndGggd2l0aCB5b3Ugd2hpbGUgZ2V0dGluZyB0aGUgUENJZQo+ID4gPiA+ID4gPiBkcml2ZXIg bWVyZ2VkLCBhbmQgd2UndmUgZXhwbGFpbmVkIHRoaXMgdG8geW91IG51bWVyb3VzIHRpbWVzLiBD b3VsZAo+ID4gPiA+ID4gPiB5b3UgcGxlYXNlIHVuZGVyc3RhbmQgdGhhdCBhbnkgb2YgeW91ciBw cm9wb3NhbCB0aGF0IHN1Z2dlc3RzIHdyaXRpbmcKPiA+ID4gPiA+ID4gZG93biBzdGF0aWMgd2lu ZG93cyBmb3IgUENJZSBkZXZpY2VzIHdpbGwgbm90IHdvcms/Cj4gPiA+ID4gPiAKPiA+ID4gPiA+ IFdoZXJlIGRpZCBJIHN1Z2dlc3Qgc3RhdGljIHdpbmRvd3MgZm9yIFBDSWUgZGV2aWNlcz8KPiA+ ID4gPiAKPiA+ID4gPiBXaGVyZSBkb2VzIHlvdXIgbmV3IHByb3Bvc2FsIGJ1eXMgdXMgYW55dGhp bmcgdXNlZnVsIGNvbXBhcmVkIHRvIHRoZQo+ID4gPiA+IGV4aXN0aW5nIFBDSWUgRFQgYmluZGlu ZyB0aGF0IGhhcyBiZWVuIGRpc2N1c3NlZCBhdCBsZW5ndGggd2l0aCB5b3U/Cj4gPiA+IAo+ID4g PiBJJ20gcHJldHR5IHN1cmUgSSBleHBsYWluZWQgdGhlIGlkZWEgYWJvdmUgb3JpZ2luYWxseSBh bmQgd2FzIGlnbm9yZWQuCj4gPiA+IEphc29uIEd1bnRob3JwZSBtaWdodCByZW1lbWJlciBiZXR0 ZXIsIGJ1dCBJIHRoaW5rIGhlIGxpa2VkIGl0IHdoZW4gSQo+ID4gPiBvcmlnaW5hbGx5IHByb3Bv c2VkIGRvaW5nIGl0IHRoaXMgd2F5Lgo+ID4gCj4gPiBJIHJlbWVtYmVyIGl0IHRvb2sgYSBiaXQg dG8gdW5kZXJzdGFuZCB5b3VyIHByb3Bvc2FsLCBidXQgSSB0aG91Z2h0IGl0Cj4gPiBjb3VsZCB3 b3JrLCBidXQgSSBhZG1pdCBJIGZvcmdldCBhbGwgdGhlIGxpdHRsZSBkZXRhaWxzIG5vdyA6KAo+ ID4gCj4gPiBBaCwgaWYgSSBjYW4ganVzdCByZXBocmFzZSBzaW1wbHkgLSB0aGUgbm90aW9uIHdh cyB0byBtb3ZlIHRoZQo+ID4gZGV0ZXJtaW5hdGlvbiBvZiB0aGUgYXBlcnR1cmUgdG8gdXNlIGR5 bm1pYyBhbGxvY2F0aW9uIGFuZCB0aGVuCj4gPiByZXN0cnVjdHVyZSB0aGUgcmFuZ2VzIGFyb3Vu ZCB0aGUgbWJ1cyB0YXJnZXQsIHNpbmNlIHRoZXkgbm8gbG9uZ2VyCj4gPiBuZWVkIHRvIGVuY29k ZSB0aGUgYXBlcnR1cmUuCj4gCj4gUmlnaHQuCj4gCj4gPiBNeSBjb25jZXJuOiBkeW5hbWljYWxs eSBzaXppbmcgdGhlIGFwZXJ0dXJlIGlzIGhhcmQuIFRoZXJlIGFyZSB0aHJlZQo+ID4gYXBlcnR1 cmVzIHRoYXQgbmVlZCB0byBiZSBwaWNrZWQsIGFuZCB0aGUgUENJIGNvcmUgY29kZSBoYXMgbm8g c3VwcG9ydAo+ID4gZm9yIGR5bmFtaWMgYXBlcnR1cmVzLiBHZXR0aW5nIHRoZSBhcGVydHVyZSBm cm9tIHRoZSBEVCBpcyBhCj4gPiBmdW5jdGlvbmFsIGNvbXByb21pc2UuCj4gCj4gQWZ0ZXIgc29t ZSBkaXNjdXNzaW9uIG9uIElSQyB3aXRoIEV6ZXF1aWVsLCBJIHRoaW5rIGl0J3MgYmVzdCB0byBs ZWF2ZQo+IHRoZSBhcGVydHVyZSBsaXN0ZWQgaW4gRFQgYnV0IHNheSBpbiB0aGUgYmluZGluZyB0 aGF0IHRoZSBPUyBtYXkKPiBvdmVycmlkZSBpdC4KPiAKClllcywgSSdsbCBzZW5kIGEgdjQgc29v biwgYW5kIEknbGwgdHJ5IHRvIGFkZHJlc3MgdGhpcyBjb3JyZWN0bHksCmFzIHlvdSdyZSBzdWdn ZXN0aW5nLgoKWy4uLl0KPiA+IElNSE8sIEkgZ28gYmFjayB0byBteSBvcmlnaW5hbCB0aG91Z2h0 cy4gVGhlcmUgaXMgbm8gcmVhbCBuZWVkIGZvciBhbnkKPiA+IG9mIHRoaXMgdG8gYmUgZHluYW1p Yywgd2UgY2FuIHVzZSB0aGUgdmFsdWVzIGluIHRoZSBEVCwgcHJlc3VtYWJseSBzZXQKPiA+IGJ5 IHRoZSBib290bG9hZGVyIGFuZCB0aGluZ3Mgd2lsbCB3b3JrIHdlbGwuCj4gPiAKPiA+IFRoZSBh ZGRlZCBjb21wbGV4aXR5IGFuZCBmYWlsdXJlIG1vZGVzIGZvciBkeW5hbWljIGlzIHNpbXBseSBu b3Qgd29ydGgKPiA+IGl0Li4KPiAKPiBJIGRvbid0IHRoaW5rIGl0J3MgdG9vIGhhcmQgdG8gYmUg cHJlcGFyZWQgZm9yIGZ1bGx5IGR5bmFtaWMgb3BlcmF0aW9uLgo+IEFzIEdyYW50IHNhaWQgaW4g aGlzIGNvbW1lbnQgb24gdjIsIHRoZSByZWFsIGNvbXBsZXhpdHkgY29tZXMgZnJvbSB0aGUKPiBm YWN0IHRoYXQgd2UgYXJlIG1peGluZyBkeW5hbWljIGFuZCBzdGF0aWMgY29uZmlndXJhdGlvbiBo ZXJlLCBhbmQKPiB0aGUgUENJZSBjb25maWd1cmF0aW9uIGlzIGluaGVyZW50bHkgZHluYW1pYy4K PiAKPiBUaGUgY2hhbmdlIEknbSBwcm9wb3Npbmcgd291bGQganVzdCBtZWFuIHRoZSBEVCByZXBy ZXNlbnRhdGlvbiByZWZsZWN0cwo+IHRoZSBkeW5hbWljIG5hdHVyZSBvZiB0aGUgUENJZSB3aW5k b3dzLgo+IAoKQWx0aG91Z2ggSSdkIGxpa2UgdGhlIGJpbmRpbmcgdG8gdGFrZSB0aGlzIGludG8g YWNjb3VudCwgZm9yIHRoZXJlJ3Mgbm8KcG9pbnQgaW4gcmVzdHJpY3RpbmcgaXQgLWEgcHJpb3Jp LSBJIGNhbid0IHNlZSAqYW55KiBhZHZhbnRhZ2Ugb24gZG9pbmcKZnVsbHkgZHluYW1pYyB3aW5k b3cgY29uZmlndXJhdGlvbiBvbiBkZXZpY2VzIHRoYXQgYXJlIGZpeGVkIGluIHRoZQpmaXJzdCBw bGFjZS4gSXQgc291bmRzIGxpa2UgYmxvYXRpbmcgdGhlIHdob2xlIHRoaW5nIHdpdGhvdXQgYSBz dHJvbmcKbmVlZC4KCi0tIApFemVxdWllbCBHYXJjw61hLCBGcmVlIEVsZWN0cm9ucwpFbWJlZGRl ZCBMaW51eCwgS2VybmVsIGFuZCBBbmRyb2lkIEVuZ2luZWVyaW5nCmh0dHA6Ly9mcmVlLWVsZWN0 cm9ucy5jb20KX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18K ZGV2aWNldHJlZS1kaXNjdXNzIG1haWxpbmcgbGlzdApkZXZpY2V0cmVlLWRpc2N1c3NAbGlzdHMu b3psYWJzLm9yZwpodHRwczovL2xpc3RzLm96bGFicy5vcmcvbGlzdGluZm8vZGV2aWNldHJlZS1k aXNjdXNzCg==