From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Clark Subject: Re: [PATCH] drm/msm: use proper memory barriers for updating tail/head Date: Tue, 3 Oct 2017 08:59:47 -0400 Message-ID: References: <20171002143711.23802-1-robdclark@gmail.com> <20171003080812.xdzymkuloam3d2cj@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20171003080812.xdzymkuloam3d2cj@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Daniel Vetter Cc: linux-arm-msm , freedreno , "dri-devel@lists.freedesktop.org" List-Id: linux-arm-msm@vger.kernel.org T24gVHVlLCBPY3QgMywgMjAxNyBhdCA0OjA4IEFNLCBEYW5pZWwgVmV0dGVyIDxkYW5pZWxAZmZ3 bGwuY2g+IHdyb3RlOgo+IE9uIE1vbiwgT2N0IDAyLCAyMDE3IGF0IDEwOjM3OjExQU0gLTA0MDAs IFJvYiBDbGFyayB3cm90ZToKPj4gRml4ZXMgaW50ZXJtaXR0ZW50IGNvcnJ1cHRpb24gb2YgY21k c3RyZWFtIGR1bXAuCj4+Cj4+IFNpZ25lZC1vZmYtYnk6IFJvYiBDbGFyayA8cm9iZGNsYXJrQGdt YWlsLmNvbT4KPgo+IFJ1bGUgb2YgbWVtb3J5IGJhcnJpZXJzOiBUaGV5IGFsd2F5cyBuZWVkIHRv IGNvbWUgaW4gcGFpcnMsIGFuZCB5b3Ugc2hvdWxkCj4gcHV0IGEgY29tbWVudCB0byBlYWNoIG9u ZSBleHBsYWluaW5nIHdoZXJlIHRoZSBvdGhlciBzaWRlIGlzLiBJLmUuIGZvciBhbGwKPiB0aGUg c3RvcmVfcmVsZWFzZSBvbmVzIHlvdSBhZGQgaGVyZSB5b3UgbmVlZCB0byBwdXQgYSBmZXcgcmVh ZF9hY3F1aXJlCj4gb25lcyBzb21ld2hlcmUgZWxzZSwgYW5kIHRoZW4gZXhwbGFpbiBob3cgdGhl eSBsaW5rLgo+Cj4gT25lIHNpZGUgb25seSBkb2Vzbid0IHJlYWxseSB3b3JrIHdpdGggYmFycmll cnMgLSBleGNlcHQgd2hlbiB5b3UncmUgbHVja3kKPiBhbmQgb24geDg2IDotKQoKZndpdywgdGhp cyBpcyBzdHJhaWdodCBvdXQgb2YgRG9jdW1lbnRhdGlvbi9jaXJjdWxhci1idWZmZXJzLnR4dAoK SSBndWVzcyBpdCBjb3VsZCByZWFkX2FjcXVpcmUgd2hlbiBjaGVja2luZyB0aGUgYXZhaWwvZnJl ZSBzcGFjZSBvbgp0aGUgY29uc3VtZXIvcHJvZHVjZXIgc2lkZS4uIG90b2ggaWYgd2Ugc2VlIGFu IG9sZCB2YWx1ZSB0aGVyZSBpdCBpcwpoYXJtbGVzcyAoaWUuIHdlIGp1c3QgZmFsbCBpbnRvIGEg d2FpdF9ldmVudCgpKS4gIEkgYXNzdW1lIHRoYXQgaXMgd2h5CnRoZSBkb2N1bWVudGF0aW9uIGRp ZG4ndCBib3RoZXIgd2l0aCBhIHJlYWRfYWNxdWlyZS4KCkJSLAotUgoKPiAtRGFuaWVsCj4+IC0t LQo+PiAgZHJpdmVycy9ncHUvZHJtL21zbS9tc21fcmQuYyB8IDQgKystLQo+PiAgMSBmaWxlIGNo YW5nZWQsIDIgaW5zZXJ0aW9ucygrKSwgMiBkZWxldGlvbnMoLSkKPj4KPj4gZGlmZiAtLWdpdCBh L2RyaXZlcnMvZ3B1L2RybS9tc20vbXNtX3JkLmMgYi9kcml2ZXJzL2dwdS9kcm0vbXNtL21zbV9y ZC5jCj4+IGluZGV4IDVjMDg3YTQyMjhmZi4uOTE4YzY1ZTE5OTY0IDEwMDY0NAo+PiAtLS0gYS9k cml2ZXJzL2dwdS9kcm0vbXNtL21zbV9yZC5jCj4+ICsrKyBiL2RyaXZlcnMvZ3B1L2RybS9tc20v bXNtX3JkLmMKPj4gQEAgLTEyMCw3ICsxMjAsNyBAQCBzdGF0aWMgdm9pZCByZF93cml0ZShzdHJ1 Y3QgbXNtX3JkX3N0YXRlICpyZCwgY29uc3Qgdm9pZCAqYnVmLCBpbnQgc3opCj4+ICAgICAgICAg ICAgICAgbiA9IG1pbihzeiwgY2lyY19zcGFjZV90b19lbmQoJnJkLT5maWZvKSk7Cj4+ICAgICAg ICAgICAgICAgbWVtY3B5KGZwdHIsIHB0ciwgbik7Cj4+Cj4+IC0gICAgICAgICAgICAgZmlmby0+ aGVhZCA9IChmaWZvLT5oZWFkICsgbikgJiAoQlVGX1NaIC0gMSk7Cj4+ICsgICAgICAgICAgICAg c21wX3N0b3JlX3JlbGVhc2UoJmZpZm8tPmhlYWQsIChmaWZvLT5oZWFkICsgbikgJiAoQlVGX1Na IC0gMSkpOwo+PiAgICAgICAgICAgICAgIHN6ICAtPSBuOwo+PiAgICAgICAgICAgICAgIHB0ciAr PSBuOwo+Pgo+PiBAQCAtMTU3LDcgKzE1Nyw3IEBAIHN0YXRpYyBzc2l6ZV90IHJkX3JlYWQoc3Ry dWN0IGZpbGUgKmZpbGUsIGNoYXIgX191c2VyICpidWYsCj4+ICAgICAgICAgICAgICAgZ290byBv dXQ7Cj4+ICAgICAgIH0KPj4KPj4gLSAgICAgZmlmby0+dGFpbCA9IChmaWZvLT50YWlsICsgbikg JiAoQlVGX1NaIC0gMSk7Cj4+ICsgICAgIHNtcF9zdG9yZV9yZWxlYXNlKCZmaWZvLT50YWlsLCAo Zmlmby0+dGFpbCArIG4pICYgKEJVRl9TWiAtIDEpKTsKPj4gICAgICAgKnBwb3MgKz0gbjsKPj4K Pj4gICAgICAgd2FrZV91cF9hbGwoJnJkLT5maWZvX2V2ZW50KTsKPj4gLS0KPj4gMi4xMy41Cj4+ Cj4+IF9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCj4+IGRy aS1kZXZlbCBtYWlsaW5nIGxpc3QKPj4gZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwo+ PiBodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZl bAo+Cj4gLS0KPiBEYW5pZWwgVmV0dGVyCj4gU29mdHdhcmUgRW5naW5lZXIsIEludGVsIENvcnBv cmF0aW9uCj4gaHR0cDovL2Jsb2cuZmZ3bGwuY2gKX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlz dHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4v bGlzdGluZm8vZHJpLWRldmVsCg==