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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF18CC433EF for ; Fri, 15 Jul 2022 06:33:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231696AbiGOGdJ convert rfc822-to-8bit (ORCPT ); Fri, 15 Jul 2022 02:33:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231649AbiGOGdE (ORCPT ); Fri, 15 Jul 2022 02:33:04 -0400 Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35EB1237D9 for ; Thu, 14 Jul 2022 23:33:01 -0700 (PDT) Received: from omf12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id A206D803A7; Fri, 15 Jul 2022 06:32:58 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: joe@perches.com) by omf12.hostedemail.com (Postfix) with ESMTPA id 391E81C; Fri, 15 Jul 2022 06:32:54 +0000 (UTC) Message-ID: <84e873c27f2426ce003e650004fe856bf72c634b.camel@perches.com> Subject: Re: [PATCH] mediatek: mt7601u: fix clang -Wformat warning From: Joe Perches To: Justin Stitt , Jakub Kicinski , Kalle Valo , "David S . Miller" , Eric Dumazet , Paolo Abeni , Matthias Brugger Cc: Nathan Chancellor , Nick Desaulniers , Tom Rix , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Date: Thu, 14 Jul 2022 23:32:53 -0700 In-Reply-To: <20220711212932.1501592-1-justinstitt@google.com> References: <20220711212932.1501592-1-justinstitt@google.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8BIT User-Agent: Evolution 3.44.1-0ubuntu1 MIME-Version: 1.0 X-Stat-Signature: 1hso3syzywufyzhw636x1fz9p96yse9u X-Rspamd-Server: rspamout01 X-Rspamd-Queue-Id: 391E81C X-Session-Marker: 6A6F6540706572636865732E636F6D X-Session-ID: U2FsdGVkX18D0NiRIZaOhSqXbeaEBffV+4ygx6yiPXw= X-HE-Tag: 1657866774-101434 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2022-07-11 at 14:29 -0700, Justin Stitt wrote: > When building with Clang we encounter this warning: > > drivers/net/wireless/mediatek/mt7601u/debugfs.c:92:6: error: format > > specifies type 'unsigned char' but the argument has type 'int' > > [-Werror,-Wformat] dev->ee->reg.start + dev->ee->reg.num - 1); > > The format specifier used is `%hhu` which describes a u8. Both > `dev->ee->reg.start` and `.num` are u8 as well. However, the expression > as a whole is promoted to an int as you cannot get smaller-than-int from > addition. Therefore, to fix the warning, use the promoted-to-type's > format specifier -- in this case `%d`. I think whenever a sizeof(unsigned type) that is less than sizeof(int) is emitted with vsprintf, the preferred format specifier should be %u not %d. > diff --git a/drivers/net/wireless/mediatek/mt7601u/debugfs.c b/drivers/net/wireless/mediatek/mt7601u/debugfs.c [] > @@ -88,7 +88,7 @@ mt7601u_eeprom_param_show(struct seq_file *file, void *data) > dev->ee->rssi_offset[0], dev->ee->rssi_offset[1]); > seq_printf(file, "Reference temp: %hhx\n", dev->ee->ref_temp); > seq_printf(file, "LNA gain: %hhx\n", dev->ee->lna_gain); > - seq_printf(file, "Reg channels: %hhu-%hhu\n", dev->ee->reg.start, > + seq_printf(file, "Reg channels: %hhu-%d\n", dev->ee->reg.start, > dev->ee->reg.start + dev->ee->reg.num - 1); And this is not a promotion of an argument to int via varargs. The arithmetic did the promotion. I suggest s/%hh/%/ for all the uses here, not just this one. checkpatch could do this somewhat automatically. Of course any changes it suggests need human review. $ ./scripts/checkpatch.pl -f drivers/net/wireless/mediatek/mt7601u/debugfs.c --show-types --types=unnecessary_modifier --fix-inplace $ git diff --stat -p drivers/net/wireless/mediatek/mt7601u/debugfs.c --- drivers/net/wireless/mediatek/mt7601u/debugfs.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt7601u/debugfs.c b/drivers/net/wireless/mediatek/mt7601u/debugfs.c index 20669eacb66ea..b7a6376e3352e 100644 --- a/drivers/net/wireless/mediatek/mt7601u/debugfs.c +++ b/drivers/net/wireless/mediatek/mt7601u/debugfs.c @@ -83,28 +83,28 @@ mt7601u_eeprom_param_show(struct seq_file *file, void *data) struct tssi_data *td = &dev->ee->tssi_data; int i; - seq_printf(file, "RF freq offset: %hhx\n", dev->ee->rf_freq_off); - seq_printf(file, "RSSI offset: %hhx %hhx\n", + seq_printf(file, "RF freq offset: %x\n", dev->ee->rf_freq_off); + seq_printf(file, "RSSI offset: %x %x\n", dev->ee->rssi_offset[0], dev->ee->rssi_offset[1]); - seq_printf(file, "Reference temp: %hhx\n", dev->ee->ref_temp); - seq_printf(file, "LNA gain: %hhx\n", dev->ee->lna_gain); - seq_printf(file, "Reg channels: %hhu-%hhu\n", dev->ee->reg.start, + seq_printf(file, "Reference temp: %x\n", dev->ee->ref_temp); + seq_printf(file, "LNA gain: %x\n", dev->ee->lna_gain); + seq_printf(file, "Reg channels: %u-%u\n", dev->ee->reg.start, dev->ee->reg.start + dev->ee->reg.num - 1); seq_puts(file, "Per rate power:\n"); for (i = 0; i < 2; i++) - seq_printf(file, "\t raw:%02hhx bw20:%02hhx bw40:%02hhx\n", + seq_printf(file, "\t raw:%02x bw20:%02x bw40:%02x\n", rp->cck[i].raw, rp->cck[i].bw20, rp->cck[i].bw40); for (i = 0; i < 4; i++) - seq_printf(file, "\t raw:%02hhx bw20:%02hhx bw40:%02hhx\n", + seq_printf(file, "\t raw:%02x bw20:%02x bw40:%02x\n", rp->ofdm[i].raw, rp->ofdm[i].bw20, rp->ofdm[i].bw40); for (i = 0; i < 4; i++) - seq_printf(file, "\t raw:%02hhx bw20:%02hhx bw40:%02hhx\n", + seq_printf(file, "\t raw:%02x bw20:%02x bw40:%02x\n", rp->ht[i].raw, rp->ht[i].bw20, rp->ht[i].bw40); seq_puts(file, "Per channel power:\n"); for (i = 0; i < 7; i++) - seq_printf(file, "\t tx_power ch%u:%02hhx ch%u:%02hhx\n", + seq_printf(file, "\t tx_power ch%u:%02x ch%u:%02x\n", i * 2 + 1, dev->ee->chan_pwr[i * 2], i * 2 + 2, dev->ee->chan_pwr[i * 2 + 1]); @@ -112,8 +112,8 @@ mt7601u_eeprom_param_show(struct seq_file *file, void *data) return 0; seq_puts(file, "TSSI:\n"); - seq_printf(file, "\t slope:%02hhx\n", td->slope); - seq_printf(file, "\t offset=%02hhx %02hhx %02hhx\n", + seq_printf(file, "\t slope:%02x\n", td->slope); + seq_printf(file, "\t offset=%02x %02x %02x\n", td->offset[0], td->offset[1], td->offset[2]); seq_printf(file, "\t delta_off:%08x\n", td->tx0_delta_offset);