From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 218B117FD for ; Mon, 6 Nov 2023 03:57:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com header.b="BlhvldTx" Received: from mail-0201.mail-europe.com (mail-0201.mail-europe.com [51.77.79.158]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAE2DF2 for ; Sun, 5 Nov 2023 19:57:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1699243066; x=1699502266; bh=As3a27QMW/BoHW+UlSXOW4dmynjX02XHuetDPzr1fAg=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=BlhvldTx+ZtolLJefmPmmfXaOWSIoBHIGgVD+Ozt4PdRogycXX5xb/xAjyTNQJkoN 1gG1i0KW01EJD/WZ929bmEkGbwsexNCyMqEXdYZC/127RtzPlTSRal2Aypr3Nuv7k+ QRpizadcihXeVXMqOcRy0VdIa3J+E3oCGMgHkzNBk/lQi1OxE9X6RsgYUjOHpHEmdV 8MiR0g/1UXnAG2bQjilDkbwTYXEEkp351zsCtQXUUHRY2QuWLVPN/6RZyay0KvoDP8 K2eOMom3LhYidTXM0riGHoot+2itGyI6MxGDnvd5NoRU15MRhhar2jMW5aWQBznbIB 6J7BGZ3Rr9bxQ== Date: Mon, 06 Nov 2023 03:57:39 +0000 To: Su Hui From: Rahul Rameshbabu Cc: ping.cheng@wacom.com, jason.gerecke@wacom.com, jikos@kernel.org, benjamin.tissoires@redhat.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] HID: wacom_sys: add error code check in wacom_feature_mapping Message-ID: <871qd31qkx.fsf@protonmail.com> In-Reply-To: <20231020090237.201029-1-suhui@nfschina.com> References: <20231020090237.201029-1-suhui@nfschina.com> Feedback-ID: 26003777:user:proton Precedence: bulk X-Mailing-List: kernel-janitors@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Fri, 20 Oct, 2023 17:02:38 +0800 "Su Hui" wrote: > hid_report_raw_event() can return error code like '-ENOMEM' if > failed, so check 'ret' to make sure all things work fine. I can agree with adding logging for error cases personally. > > Signed-off-by: Su Hui > --- > drivers/hid/wacom_sys.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c > index 3f704b8072e8..1f898d4ee708 100644 > --- a/drivers/hid/wacom_sys.c > +++ b/drivers/hid/wacom_sys.c > @@ -320,6 +320,8 @@ static void wacom_feature_mapping(struct hid_device *= hdev, > =09=09=09if (ret =3D=3D n && features->type =3D=3D HID_GENERIC) { > =09=09=09=09ret =3D hid_report_raw_event(hdev, > =09=09=09=09=09HID_FEATURE_REPORT, data, n, 0); > +=09=09=09=09if (ret) > +=09=09=09=09=09hid_warn(hdev, "failed to report feature\n"); I think we should report the returned error information as well. https://docs.kernel.org/core-api/printk-formats.html#error-pointers Typically what I do is use ERR_PTR in tandem with the %pe modifier for printing errors. > =09=09=09} else if (ret =3D=3D 2 && features->type !=3D HID_GENERIC) { > =09=09=09=09features->touch_max =3D data[1]; > =09=09=09} else { > @@ -381,6 +383,8 @@ static void wacom_feature_mapping(struct hid_device *= hdev, > =09=09if (ret =3D=3D n) { > =09=09=09ret =3D hid_report_raw_event(hdev, HID_FEATURE_REPORT, > =09=09=09=09=09=09 data, n, 0); > +=09=09=09if (ret) > +=09=09=09=09hid_warn(hdev, "failed to report feature\n"); > =09=09} else { > =09=09=09hid_warn(hdev, "%s: could not retrieve sensor offsets\n", > =09=09=09=09 __func__); -- Thanks for the patch, Rahul Rameshbabu