From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: inconsistent lock state with usbnet/asix usb ethernet and xhci Date: Mon, 05 Mar 2018 11:09:02 -0800 Message-ID: <1520276942.109662.9.camel@gmail.com> References: <1519740421.7296.6.camel@gmail.com> <1519744167.7296.8.camel@gmail.com> <1519744400.7296.10.camel@gmail.com> <1519747675.2649.3.camel@suse.com> <02679502-cf6e-8714-e879-50a922c5d976@samsung.com> <1520250367.3990.9.camel@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1520250367.3990.9.camel@suse.com> Sender: linux-kernel-owner@vger.kernel.org To: Oliver Neukum , Marek Szyprowski Cc: LKML , 'Linux Samsung SOC' , Linux USB Mailing List , netdev@vger.kernel.org, Dean Jenkins List-Id: linux-samsung-soc@vger.kernel.org On Mon, 2018-03-05 at 12:46 +0100, Oliver Neukum wrote: > On Mon, 2018-03-05 at 08:45 +0100, Marek Szyprowski wrote: > > Hi Oliver, > > > > On 2018-02-27 17:07, Oliver Neukum wrote: > > > Am Dienstag, den 27.02.2018, 07:13 -0800 schrieb Eric Dumazet: > > > > On Tue, 2018-02-27 at 07:09 -0800, Eric Dumazet wrote: > > > > > > > > > > Note that for this one, it seems we also could perform stats > > > > > updates in > > > > > BH context, since skb is queued via defer_bh() > > > > > > > > > > But simplicity wins I guess. > > > > > > > > Thinking more about this, I am not sure we have any guarantee > > > > that TX > > > > and RX can not run on multiple cpus. > > > > > > > > Using an unique syncp is not going to be safe, even if we make > > > > lockdep > > > > happy enough with the local_irq save/restore. > > > > > > Unfortunately you are right. It is not guaranteed for some > > > hardware. > > > > Does it mean that the fix proposed by Eric is not the proper > > solution? > > For asix it should work, but asix is unlikely to be the only driver > with that issue. 32 bit recieves less testing nowadays. Yes, although the lockdep part could be enforced in 64bit if we really care. I will send a patch using two different sync (one for RX, one for TX) 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: inconsistent lock state with usbnet/asix usb ethernet and xhci From: Eric Dumazet Message-Id: <1520276942.109662.9.camel@gmail.com> Date: Mon, 05 Mar 2018 11:09:02 -0800 To: Oliver Neukum , Marek Szyprowski Cc: LKML , 'Linux Samsung SOC' , Linux USB Mailing List , netdev@vger.kernel.org, Dean Jenkins List-ID: T24gTW9uLCAyMDE4LTAzLTA1IGF0IDEyOjQ2ICswMTAwLCBPbGl2ZXIgTmV1a3VtIHdyb3RlOgo+ IE9uIE1vbiwgMjAxOC0wMy0wNSBhdCAwODo0NSArMDEwMCwgTWFyZWsgU3p5cHJvd3NraSB3cm90 ZToKPiA+IEhpIE9saXZlciwKPiA+IAo+ID4gT24gMjAxOC0wMi0yNyAxNzowNywgT2xpdmVyIE5l dWt1bSB3cm90ZToKPiA+ID4gQW0gRGllbnN0YWcsIGRlbiAyNy4wMi4yMDE4LCAwNzoxMyAtMDgw MCBzY2hyaWViIEVyaWMgRHVtYXpldDoKPiA+ID4gPiBPbiBUdWUsIDIwMTgtMDItMjcgYXQgMDc6 MDkgLTA4MDAsIEVyaWMgRHVtYXpldCB3cm90ZToKPiA+ID4gPiA+IAo+ID4gPiA+ID4gTm90ZSB0 aGF0IGZvciB0aGlzIG9uZSwgaXQgc2VlbXMgd2UgYWxzbyBjb3VsZCBwZXJmb3JtIHN0YXRzCj4g PiA+ID4gPiB1cGRhdGVzIGluCj4gPiA+ID4gPiBCSCBjb250ZXh0LCBzaW5jZSBza2IgaXMgcXVl dWVkIHZpYSBkZWZlcl9iaCgpCj4gPiA+ID4gPiAKPiA+ID4gPiA+IEJ1dCBzaW1wbGljaXR5IHdp bnMgSSBndWVzcy4KPiA+ID4gPiAKPiA+ID4gPiBUaGlua2luZyBtb3JlIGFib3V0IHRoaXMsIEkg YW0gbm90IHN1cmUgd2UgaGF2ZSBhbnkgZ3VhcmFudGVlCj4gPiA+ID4gdGhhdCBUWAo+ID4gPiA+ IGFuZCBSWCBjYW4gbm90IHJ1biBvbiBtdWx0aXBsZSBjcHVzLgo+ID4gPiA+IAo+ID4gPiA+IFVz aW5nIGFuIHVuaXF1ZSBzeW5jcCBpcyBub3QgZ29pbmcgdG8gYmUgc2FmZSwgZXZlbiBpZiB3ZSBt YWtlCj4gPiA+ID4gbG9ja2RlcAo+ID4gPiA+IGhhcHB5IGVub3VnaCB3aXRoIHRoZSBsb2NhbF9p cnEgc2F2ZS9yZXN0b3JlLgo+ID4gPiAKPiA+ID4gVW5mb3J0dW5hdGVseSB5b3UgYXJlIHJpZ2h0 LiBJdCBpcyBub3QgZ3VhcmFudGVlZCBmb3Igc29tZQo+ID4gPiBoYXJkd2FyZS4KPiA+IAo+ID4g RG9lcyBpdCBtZWFuIHRoYXQgdGhlIGZpeCBwcm9wb3NlZCBieSBFcmljIGlzIG5vdCB0aGUgcHJv cGVyCj4gPiBzb2x1dGlvbj8KPiAKPiBGb3IgYXNpeCBpdCBzaG91bGQgd29yaywgYnV0IGFzaXgg aXMgdW5saWtlbHkgdG8gYmUgdGhlIG9ubHkgZHJpdmVyCj4gd2l0aCB0aGF0IGlzc3VlLiAzMiBi aXQgcmVjaWV2ZXMgbGVzcyB0ZXN0aW5nIG5vd2FkYXlzLgoKWWVzLCBhbHRob3VnaCB0aGUgbG9j a2RlcCBwYXJ0IGNvdWxkIGJlIGVuZm9yY2VkIGluIDY0Yml0IGlmIHdlIHJlYWxseQpjYXJlLgoK SSB3aWxsIHNlbmQgYSBwYXRjaCB1c2luZyB0d28gZGlmZmVyZW50IHN5bmMgKG9uZSBmb3IgUlgs IG9uZSBmb3IgVFgpCi0tLQpUbyB1bnN1YnNjcmliZSBmcm9tIHRoaXMgbGlzdDogc2VuZCB0aGUg bGluZSAidW5zdWJzY3JpYmUgbGludXgtdXNiIiBpbgp0aGUgYm9keSBvZiBhIG1lc3NhZ2UgdG8g bWFqb3Jkb21vQHZnZXIua2VybmVsLm9yZwpNb3JlIG1ham9yZG9tbyBpbmZvIGF0ICBodHRwOi8v dmdlci5rZXJuZWwub3JnL21ham9yZG9tby1pbmZvLmh0bWwK