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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5D0DAC433EF for ; Mon, 11 Apr 2022 10:28:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VUfhVXgiG8DrVD+/foRBHuQeiKyBB+JsACUL07D1wv0=; b=JSWszqEC8z7QgO RhJfYmspPTLP6piY8C3QxvBhUEpY0rexpqidqW/dCNDM/HA6KDqejTdWzFUTMkRSuShx3U+jMTtBD wpHgMHEdvEWlj0iijpfTidb4CLDyia6zWvfRFaMzAUb7zB2P5ahkWj03mLkSu+JsjJY+kx7uCFzK3 VRuEPmfC6k/TOMwk500AAl0YyIzF074CtfTN/8h6VbY8d4vkqR/m5fuV2lBXJGCaCe0pVuQbsfFTf zlFT91Z/qtLgxeTLePHfX+A350UryO9MuwSqT7fmP0zlEOaRoWJeYB97BeYpdfEiY6+Nuzw0m92VE N/03DMt/rorupKShzVyQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ndrGK-008JuG-8k; Mon, 11 Apr 2022 10:27:12 +0000 Received: from muru.com ([72.249.23.125]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ndqmu-0086HF-ES for linux-arm-kernel@lists.infradead.org; Mon, 11 Apr 2022 09:56:50 +0000 Received: from localhost (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 625B081D0; Mon, 11 Apr 2022 09:54:15 +0000 (UTC) Date: Mon, 11 Apr 2022 12:56:44 +0300 From: Tony Lindgren To: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= Cc: Greg Kroah-Hartman , Jiri Slaby , Johan Hovold , linux-serial@vger.kernel.org, kernel@pengutronix.de, Steffen Trumtrar , linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, regressions@lists.linux.dev Subject: Re: [PATCH] serial: 8250: Return early in .start_tx() if there are no chars to send Message-ID: References: <20220217211839.443039-1-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220411_025648_584449_A90B6DAD X-CRM114-Status: GOOD ( 17.91 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org KiBUb255IExpbmRncmVuIDx0b255QGF0b21pZGUuY29tPiBbMjIwNDA3IDEzOjI1XToKPiBIaSwK PiAKPiAqIFV3ZSBLbGVpbmUtS8O2bmlnIDx1LmtsZWluZS1rb2VuaWdAcGVuZ3V0cm9uaXguZGU+ IFs3MDAxMDEgMDI6MDBdOgo+ID4gRnJvbTogU3RlZmZlbiBUcnVtdHJhciA8cy50cnVtdHJhckBw ZW5ndXRyb25peC5kZT4KPiA+IAo+ID4gRG9uJ3Qgc3RhcnQgdGhlIHdob2xlIGNoYWluIGZvciBU WCBpZiB0aGVyZSBpcyBubyBkYXRhIHRvIHNlbmQuIFRoaXMgaXMKPiA+IG1vc3RseSByZWxldmFu dCBmb3IgcnM0ODUgbW9kZSBhcyB0aGVyZSBtaWdodCBiZSBydHMtYmVmb3JlLXNlbmQgYW5kCj4g PiBydHMtYWZ0ZXItc2VuZCBkZWxheXMgaW52b2x2ZWQuCj4gPiAKPiA+IFNpZ25lZC1vZmYtYnk6 IFN0ZWZmZW4gVHJ1bXRyYXIgPHMudHJ1bXRyYXJAcGVuZ3V0cm9uaXguZGU+Cj4gPiBTaWduZWQt b2ZmLWJ5OiBVd2UgS2xlaW5lLUvDtm5pZyA8dS5rbGVpbmUta29lbmlnQHBlbmd1dHJvbml4LmRl Pgo+ID4gLS0tCj4gPiBIZWxsbywKPiA+IAo+ID4gYSBmZXcgb3RoZXIgZHJpdmVycyBoYXZlIHN1 Y2ggYW4gZWFybHkgZXhpdCBhbHJlYWR5IChpbXgsIHN0bTMyLXVzYXJ0KS4KPiA+IEkgd29uZGVy IGlmIGl0IGFwcGxpZXMgdG8gYWxsIFVBUlQgZHJpdmVycyB0aGF0IHRoZXJlIGlzIG5vdGhpbmcg dG8gZG8KPiA+IGluIC5zdGFydF90eCgpIGlmIHRoZSBjaXJjIGJ1ZmZlciBpcyBlbXB0eSBhbmQg dGhlcmUgaXMgbm8geF9jaGFyIHRvCj4gPiBzZW5kLiBJbiB0aGlzIGNhc2UgaXQgd291bGQgYmUg bW9yZSBzZW5zaWJsZSB0byBlbnN1cmUgaW4gc2VyaWFsX2NvcmUKPiA+IHRoYXQgLnN0YXJ0X3R4 KCkgaXMgb25seSBldmVyIGNhbGxlZCBpZiB0aGVyZSBpcyBzb21ldGhpbmcgdG8gZG8uCj4gCj4g VGhpcyBwYXRjaCBzZWVtcyB0byBjYXVzZSBhIHJ1bnRpbWUgUE0gcmVncmVzc2lvbiBpbiB2NS4x OC1yYzEgd2hlcmUKPiA4MjUwIGlzIG5ldmVyIGlkbGVkIGZvciBvbWFwcy4KPiAKPiBMb29rcyBs aWtlIHRoZSByZXR1cm4gYWRkZWQgaGVyZSBpcyBub3QgcGFpcmVkIHdpdGggcHV0IGZvciB0aGUK PiBzZXJpYWw4MjUwX3JwbV9nZXRfdHgoKSBjYWxsIGFib3ZlPwoKRllJIEkganVzdCBwb3N0ZWQg dHdvIGZpeGVzIGZvciB0aGVzZSBlYXJseSByZXR1cm4gY2FzZXM6CgpodHRwczovL2xvcmUua2Vy bmVsLm9yZy9saW51eC1zZXJpYWwvMjAyMjA0MTEwOTQ4MDUuNDU2OTYtMS10b255QGF0b21pZGUu Y29tL1QvI3QKClJlZ2FyZHMsCgpUb255CgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1haWxpbmcgbGlzdApsaW51eC1hcm0t a2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFp bG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg==