From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: RMW considered harmful (was: Re: [PATCH 2/2] drm/i915/icl: Enable TRANSCODER PORT SYNC for tiled displays across separate ports) Date: Thu, 28 Mar 2019 11:18:56 +0200 Message-ID: <87lg0z2w73.fsf@intel.com> References: <20190322015939.23189-1-manasi.d.navare@intel.com> <20190322015939.23189-2-manasi.d.navare@intel.com> <87va0bb6ce.fsf@intel.com> <20190322131603.GR3888@intel.com> <20190322175801.GB27582@intel.com> <20190322180949.GI3888@intel.com> <20190322184421.GA28038@intel.com> <20190322184656.GK3888@intel.com> <874l7ubtfi.fsf@intel.com> <20190322194008.GB28038@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9B84E6E338 for ; Thu, 28 Mar 2019 09:16:15 +0000 (UTC) In-Reply-To: <20190322194008.GB28038@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Manasi Navare Cc: Daniel Vetter , intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org T24gRnJpLCAyMiBNYXIgMjAxOSwgTWFuYXNpIE5hdmFyZSA8bWFuYXNpLmQubmF2YXJlQGludGVs LmNvbT4gd3JvdGU6Cj4gT24gRnJpLCBNYXIgMjIsIDIwMTkgYXQgMDk6Mjg6MDFQTSArMDIwMCwg SmFuaSBOaWt1bGEgd3JvdGU6Cj4+IE9uIEZyaSwgMjIgTWFyIDIwMTksIFZpbGxlIFN5cmrDpGzD pCA8dmlsbGUuc3lyamFsYUBsaW51eC5pbnRlbC5jb20+IHdyb3RlOgo+PiA+IE9uIEZyaSwgTWFy IDIyLCAyMDE5IGF0IDExOjQ0OjIxQU0gLTA3MDAsIE1hbmFzaSBOYXZhcmUgd3JvdGU6Cj4+ID4+ IE9uIEZyaSwgTWFyIDIyLCAyMDE5IGF0IDA4OjA5OjUwUE0gKzAyMDAsIFZpbGxlIFN5cmrDpGzD pCB3cm90ZToKPj4gPj4gPiBJbiB0aGF0IGNhc2UgdGhlcmUgaXMgbm8gcG9pbnQgaW4gZG9pbmcg YSBybXcuCj4+ID4+IAo+PiA+PiBCdXQgaXNudCBpdCBhbHdheXMgYSBnb29kIGlkZWEgdG8gZG8g cm13PyBJIG1lYW4gd2hhdCBpZiB0aGUgbWFzdGVyCj4+ID4+IHNlbGVjdCB3YXMgc2V0IHRvIHNv bWV0aGluZyBlbHNlIGVhcmxpZXI/Cj4+ID4KPj4gPiBSTVcgaXMgdGhlIHJvb3Qgb2YgbWFueSBl dmlscy4gSXQgc2hvdWxkIGJlIGF2b2lkZWQgdW5sZXNzIHRoZXJlIGlzIGEKPj4gPiByZWFsbHkg Y29tcGVsbGluZyByZWFzb24gdG8gdXNlIGl0Lgo+PiAKPj4gSGVhciwgaGVhciEKPj4gCj4+IFdl IGhhdmUgdGhlIHNvZnR3YXJlIHN0YXRlIHRoYXQgd2Ugd2FudCB0byB3cml0ZSB0byB0aGUgaGFy ZHdhcmUuIElmIHdlCj4+IHVzZSBSTVcgdG8gZG8gdGhpcywgaXQgbWlnaHQgYWxsIHdvcmsgYnkg Y29pbmNpZGVuY2UgZHVlIHRvIHRoZSBvbGQKPj4gdmFsdWVzIGluIHRoZSByZWdpc3RlcnMsIG9y IGl0IG1pZ2h0IGp1c3QgYXMgd2VsbCBicmVhayBieSBjb2luY2lkZW5jZQo+PiBkdWUgdG8gc29t ZSBnYXJiYWdlIGluIHRoZSByZWdpc3RlcnMuCj4+IAo+PiBJbiBtb3N0IGNhc2VzLCB0aGVyZSBz aG91bGQgb25seSBiZSBvbmUgcGxhY2UgdGhhdCB3cml0ZXMgYSBwYXJ0aWN1bGFyCj4+IGRpc3Bs YXkgcmVnaXN0ZXIgZHVyaW5nIG1vZGVzZXQuIFNvbWV0aW1lcyB0aGlzIGlzbid0IHBvc3NpYmxl LCBhbmQgUk1XCj4+IGlzIHJlcXVpcmVkLgo+PiAKPj4gU29tZSByZWdpc3RlcnMgYWxzbyBoYXZl IHJlc2VydmVkIGJpdHMgcG90ZW50aWFsbHkgdXNlZCBieSB0aGUgaGFyZHdhcmUKPj4gdGhhdCBt dXN0IG5vdCBiZSBjaGFuZ2VkLCBhbmQgUk1XIGlzIHJlcXVpcmVkLiBUaGVzZSBhcmUgZG9jdW1l bnRlZCBpbgo+PiBic3BlYy4KPj4gCj4+IEJSLAo+PiBKYW5pLgo+Pgo+Cj4gVGhhbmtzIGZvciB0 aGUgZXhwbGFuYXRpb24uIEl0IGRvZXMgbWFrZSBzZW5zZSBub3cgdGhhdCB3ZSBhcmUgZG9pbmcg YQo+IGZ1bGwgbW9kZXNldCwgd2Ugc2hvdWxkIGp1c3QgYmUgdGhlbiB3cml0aW5nIHRoZSB2YWx1 ZSBkaXJlY3RseT8gIFRoZQo+IG9ubHkgY29uY2VybiBJIGhhdmUgaXMgdGhhdCBzYXkgRFNJIGNv ZGUgc2V0cyB0aGlzIHNvbWV3aGVyZSBlbHMgZWluCj4gdGhlIG1vZGVzZXQgcGF0aCwgdGhlbiB3 ZSB3b3VsZCBuZWVkIHRvIG1vZGlmeSB0aGlzIHRvIGRvIFJNVyBvcgo+IGFsd2F5cyBtYWtlIHN1 cmUgRFNJIGFsc28gdXNlcyB0aGUgc2FtZSBmdW5jdGlvbiBmb3Igd3JpdGluZyB0byB0aGlzCj4g cmVnLiAgV2hhdCBkbyB5b3Ugc3VnZ2VzdCBkb2luZyBub3c/CgpJIHRoaW5rIGFsbCBlbmNvZGVy cyBpbiBhIHRpbGUgZ3JvdXAgYXJlIGFsd2F5cyBvZiB0aGUgc2FtZSB0eXBlLgoKSWYgdGhlIHRp bGUgZ3JvdXBpbmcgaW4geW91ciBwYXRjaCBpcyBiYXNlZCBwdXJlbHkgb24gRURJRCwgd2UgbWF5 IG5lZWQKdG8gZW5mb3JjZSB0aGlzLiBTdXJlbHkgZ2VubG9jayBvbmx5IHdvcmtzIG9uIGVuY29k ZXJzIG9mIHRoZSBzYW1lIHR5cGU/CgpJbiBhbnkgY2FzZSBEU0kgKGF0IGxlYXN0IGN1cnJlbnRs eSkgZG9lcyBub3QgdXNlIHRpbGUgZ3JvdXBzLCBhbmQgd2lsbApuZXZlciBiZSBtaXhlZCB1cCBp biBub24tRFNJIHRpbGUgZ3JvdXBzLiBUaGUgRFNJIHRyYW5zY29kZXJzIGFyZQpzZXBhcmF0ZSBm cm9tIG90aGVyIHRyYW5zY29kZXJzLCBzbyB3ZSdyZSBub3Qgd3JpdGluZyB0aGUgc2FtZSByZWdp c3RlcnMKaGVyZS4KCi0tLQoKTG9va2luZyBhdCB0aGUgY29kZSwgSSBhbSB3b25kZXJpbmcgaWYg dGhpcyBzaG91bGQgYmUgcHVzaGVkIHRvIGVuY29kZXIKaG9va3MgaW5zdGVhZCBvZiBhZGRpbmcg aW50byBjcnRjIGVuYWJsZS4KCkJSLApKYW5pLgoKCgotLSAKSmFuaSBOaWt1bGEsIEludGVsIE9w ZW4gU291cmNlIEdyYXBoaWNzIENlbnRlcgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fXwpJbnRlbC1nZnggbWFpbGluZyBsaXN0CkludGVsLWdmeEBsaXN0cy5m cmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0 aW5mby9pbnRlbC1nZng=