From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [BUG] mt76x0u: Probing issues on Raspberry Pi 3 B+ From: Stanislaw Gruszka Message-Id: <20190212131542.GC12906@redhat.com> Date: Tue, 12 Feb 2019 14:15:43 +0100 To: Lorenzo Bianconi Cc: Alan Stern , Stefan Wahren , Felix Fietkau , Doug Anderson , Minas Harutyunyan , USB list , linux-wireless List-ID: T24gVHVlLCBGZWIgMTIsIDIwMTkgYXQgMTI6NTg6NDNQTSArMDEwMCwgTG9yZW56byBCaWFuY29u aSB3cm90ZToKPiA+ICsJdXNiX2ZpbGxfYnVsa191cmIoYnVmLT51cmIsIHVkZXYsIHBpcGUsIE5V TEwsIGJ1Zi0+bGVuLCBjb21wbGV0ZV9mbiwKPiA+ICsJCQkgIGNvbnRleHQpOwo+ID4gKwo+ID4g KwlpZiAodWRldi0+YnVzLT5zZ190YWJsZXNpemUgPiAwKSB7Cj4gPiArCQlidWYtPnVyYi0+bnVt X3NncyA9IGJ1Zi0+bnVtX3NnczsKPiA+ICsJfSBlbHNlIHsKPiA+ICsJCVdBUk5fT05fT05DRShi dWYtPm51bV9zZ3MgIT0gMSk7Cj4gPiArCQkvKiBTZWUgdXNiX3NnX2luaXQoKSAqLwo+ID4gKwkJ YnVmLT51cmItPm51bV9zZ3MgPSAwOwo+ID4gKwkJaWYgKCFQYWdlSGlnaE1lbShzZ19wYWdlKGJ1 Zi0+dXJiLT5zZykpKQo+ID4gKwkJCWJ1Zi0+dXJiLT50cmFuc2Zlcl9idWZmZXIgPSBzZ192aXJ0 KGJ1Zi0+dXJiLT5zZyk7Cj4gCj4gcGxlYXNlIGNvcnJlY3QgbWUgaWYgSSBhbSB3cm9uZyBidXQg ZG9pbmcgc28gd2Ugd2lsbCB1c2UgdHJhbnNmZXJfYnVmZmVyCj4gZm9yIDk1JSBvZiB0aGUgdXNl IGNhc2VzLCByaWdodD8gSWYgc28gd2h5IG5vdCBrZWVwIGl0IHNpbXBsZSBhbmQgYWx3YXlzCj4g dXNlIGl0IHdoZW4gc2dfdGFibGVzaXplIGlzIDAgKGF2b2lkaW5nIFNHIEkvTyk/Cj4KPiBCdHcg dGhpcyBpcyB3aGF0IEkgcHJvcG9zZWQgd2l0aCB0aGUgUkZDIHNlcmllcyBhY3R1YWxseSA6KSAo YWx3YXlzIHVzZQo+IHRyYW5zZmVyX2J1ZmZlciBpbiB0aGUgdXNiIDIuMCBjYXNlKQoKQmVjYXVz ZSB0aGlzIHdheSB3ZSBkbyBub3QgY2hhbmdlIGFsbG9jYXRpb24gbWV0aG9kICh1c2UgU0cgYWxs b2NhdGlvbikKd2hhdCBpcyBzaW1wbGVyIElNSE8gdGhhbiBoYXZpbmcgdHdvIGJ1ZmZlciBhbGxv Y2F0aW9uIG1ldGhvZHMuCgpBbmQgdGhpcyB3YXkgd2UgZG8gbm90IGhpZGUgcHJvYmxlbXMgd2l0 aCBTRyBhbGxvY2F0aW9uIGFuZCB0ZXN0IGl0LgoKQWRkaXRpb25hbGx5IHRoaXMgcGF0Y2ggYWRk cmVzcyBhY3R1YWwgYnVnOiB1c2luZyB3cm9uZyB1cmItPm51bV9zZ3MgYW5kCmNhbiBiZSBlYXNp ZXIgdG8gYmFja3BvcnQgdG8gb2xkZXIgcmVsZWFzZXMgdGhhbiA0IHBhdGNoIHNlcmllcy4gCgpT dGFuaXNsYXcK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65C99C282C4 for ; Tue, 12 Feb 2019 13:15:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C6CB214DA for ; Tue, 12 Feb 2019 13:15:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729009AbfBLNPq (ORCPT ); Tue, 12 Feb 2019 08:15:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47046 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727312AbfBLNPq (ORCPT ); Tue, 12 Feb 2019 08:15:46 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7573980481; Tue, 12 Feb 2019 13:15:45 +0000 (UTC) Received: from localhost (ovpn-204-125.brq.redhat.com [10.40.204.125]) by smtp.corp.redhat.com (Postfix) with ESMTP id 67FB31992A; Tue, 12 Feb 2019 13:15:44 +0000 (UTC) Date: Tue, 12 Feb 2019 14:15:43 +0100 From: Stanislaw Gruszka To: Lorenzo Bianconi Cc: Alan Stern , Stefan Wahren , Felix Fietkau , Doug Anderson , Minas Harutyunyan , USB list , linux-wireless Subject: Re: [BUG] mt76x0u: Probing issues on Raspberry Pi 3 B+ Message-ID: <20190212131542.GC12906@redhat.com> References: <20190211173315.GE6292@redhat.com> <20190212093035.GB12906@redhat.com> <20190212115842.GA24197@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190212115842.GA24197@localhost.localdomain> User-Agent: Mutt/1.8.3 (2017-05-23) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 12 Feb 2019 13:15:45 +0000 (UTC) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Tue, Feb 12, 2019 at 12:58:43PM +0100, Lorenzo Bianconi wrote: > > + usb_fill_bulk_urb(buf->urb, udev, pipe, NULL, buf->len, complete_fn, > > + context); > > + > > + if (udev->bus->sg_tablesize > 0) { > > + buf->urb->num_sgs = buf->num_sgs; > > + } else { > > + WARN_ON_ONCE(buf->num_sgs != 1); > > + /* See usb_sg_init() */ > > + buf->urb->num_sgs = 0; > > + if (!PageHighMem(sg_page(buf->urb->sg))) > > + buf->urb->transfer_buffer = sg_virt(buf->urb->sg); > > please correct me if I am wrong but doing so we will use transfer_buffer > for 95% of the use cases, right? If so why not keep it simple and always > use it when sg_tablesize is 0 (avoiding SG I/O)? > > Btw this is what I proposed with the RFC series actually :) (always use > transfer_buffer in the usb 2.0 case) Because this way we do not change allocation method (use SG allocation) what is simpler IMHO than having two buffer allocation methods. And this way we do not hide problems with SG allocation and test it. Additionally this patch address actual bug: using wrong urb->num_sgs and can be easier to backport to older releases than 4 patch series. Stanislaw