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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 7AD9FC43381 for ; Wed, 20 Feb 2019 15:18:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46C43206BB for ; Wed, 20 Feb 2019 15:18:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726627AbfBTPSL (ORCPT ); Wed, 20 Feb 2019 10:18:11 -0500 Received: from mail.steuer-voss.de ([85.183.69.95]:34232 "EHLO mail.steuer-voss.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725804AbfBTPSL (ORCPT ); Wed, 20 Feb 2019 10:18:11 -0500 X-Virus-Scanned: Debian amavisd-new at mail.steuer-voss.de Received: by mail.steuer-voss.de (Postfix, from userid 1000) id E4FCE4D065; Wed, 20 Feb 2019 16:18:04 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by mail.steuer-voss.de (Postfix) with ESMTP id E0A4C4D05B; Wed, 20 Feb 2019 16:18:04 +0100 (CET) Date: Wed, 20 Feb 2019 16:18:04 +0100 (CET) From: Nikolaus Voss X-X-Sender: nv@fox.voss.local To: Guenter Roeck cc: Heikki Krogerus , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2] usb: typec: tps6598x: handle block writes separately with plain-I2C adapters In-Reply-To: Message-ID: References: <20180425142209.30745-1-heikki.krogerus@linux.intel.com> <20190220110017.BFA344CE86@mail.steuer-voss.de> <20190220125731.02E274CFE0@mail.steuer-voss.de> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 20 Feb 2019, Guenter Roeck wrote: > On 2/20/19 4:57 AM, Nikolaus Voss wrote: >> Commit 1a2f474d328f handles block _reads_ separately with plain-I2C >> adapters, but the problem described with regmap-i2c not handling >> SMBus block transfers (i.e. read and writes) correctly also exists >> with writes. >> >> As workaround, this patch adds a block write function the same way >> 1a2f474d328f adds a block read function. >> >> Fixes: 1a2f474d328f ("usb: typec: tps6598x: handle block reads separately >> with plain-I2C adapters") >> Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery >> controllers") >> Signed-off-by: Nikolaus Voss >> --- >> v2: fix tps6598x_exec_cmd also >> --- >> drivers/usb/typec/tps6598x.c | 26 ++++++++++++++++++++------ >> 1 file changed, 20 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c >> index c84c8c189e90..c54b73fb2a2f 100644 >> --- a/drivers/usb/typec/tps6598x.c >> +++ b/drivers/usb/typec/tps6598x.c >> @@ -110,6 +110,20 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void >> *val, size_t len) >> return 0; >> } >> +static int tps6598x_block_write(struct tps6598x *tps, u8 reg, >> + void *val, size_t len) >> +{ >> + u8 data[len + 1]; >> + > > You should use TPS_MAX_LEN + 1 here to avoid the variable length array. > See upstream commit 0bb95f80a38f8 ("Makefile: Globally enable VLA warning") > and 8d361fa2c29dc ("usb: typec: tps6598x: Remove VLA usage"). Not sure if > the WARN_ON introduced by 8d361fa2c29dc is really needed; I dislike > unnecessary runtime checks. Thanks for the pointer, I fixed this... Nikolaus