From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 16AAB282F1B for ; Tue, 2 Jun 2026 05:43:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780379029; cv=none; b=LCa2ouEtlN7Iksr2SqngzaK+QVxjoANXhUpmVVISJ0Jexw7qP4z5bszs42kl/+C/QCAEad5MKpco4mXN4a/q2rZaOaM6os1MQ51jwEidRozPoKLnAxagEuBVLJSsrlLTYWpxKxsmMwfYOsMV3WKuekSpZ9mMTIXz4clLM2YgtDY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780379029; c=relaxed/simple; bh=FHD0UBxiTs5IlIlXe1P4HdWzbVryhYEac7as0UECJ9s=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=c+XogxlCm8XYKZsLaVLlKC6l+WxInBM4xiGZScrczX4BGmW7psUhfwrg17vJvaKboU5oY9VWO0bI04DNPFOYz5Nl2gQi+XEzvapGGozDUCqSa6VuO0FYXGzvIWuO2iXlyBJ/UnK5roKCSNySEKSZPDjvEUFjKMqWlZuIISywJyc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JYAkLoHx; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JYAkLoHx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D55F1F00893; Tue, 2 Jun 2026 05:43:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780379027; bh=HO5T4hY4oc72i5yAiqIBqEAKJnsVhjoYb+g6SW4aadk=; h=Date:From:Subject:To:Cc:References:In-Reply-To; b=JYAkLoHxgLsddiRyD6WgoC6u2YtzcpUd5X6eajBqOUdW3sCf9sHmY8x8vjwdWpFok imRiFit2XT9p8560qsmT4YTu1OrGyID9DR2t2ZaXJy+nsh80bySUqmgnM/gKCJFNKa j/8nrzLtjtMvPX75KIcHkucxkwC912HA0mjs1V+X9bVrLDVNfDmbjMLBQUHoP+YYQM wU81CadENp+5ikPruN1NogklTtfq6dO+KpMviEWy3JJ31sSOZ3hZLIe4FVFx4gqd9j z0kunfjrhL0WdUzdwOTUyUjhOcniUSXZ3C/kKLH+qGofeyI5c+NfreGUtTHQR7HWDd MFQMOvW4dG4dA== Message-ID: <39961362-0a9e-434c-85f2-2f9f5c7846a9@kernel.org> Date: Tue, 2 Jun 2026 07:43:42 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Hans Verkuil Subject: Re: [PATCH v4 1/4] drm/scdc-helper: Don't use ssize_t return type for scdc_read/write To: Nicolas Frattaroli , Jani Nikula , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Daniel Stone Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com References: <20260527-scdc-link-health-v4-0-622ea40a1f59@collabora.com> <20260527-scdc-link-health-v4-1-622ea40a1f59@collabora.com> Content-Language: en-US, nl In-Reply-To: <20260527-scdc-link-health-v4-1-622ea40a1f59@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 27/05/2026 16:03, Nicolas Frattaroli wrote: > drm_scdc_read and drm_scdc_write, both of which are only used within > drm_scdc_helper (although exported), use a ssize_t as their return type. > > This would make sense if they returned the number of bytes read/written > on success, and negative errno otherwise. However, they return 0 on > success. > > Demote them to "int" as their return type, in order to avoid needlessly > using 64 bits when less suffices. > > No functional change. Reviewed-by: Hans Verkuil Regards, Hans > > Reviewed-by: Luca Ceresoli > Signed-off-by: Nicolas Frattaroli > --- > drivers/gpu/drm/display/drm_scdc_helper.c | 8 ++++---- > include/drm/display/drm_scdc_helper.h | 8 ++++---- > 2 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/display/drm_scdc_helper.c b/drivers/gpu/drm/display/drm_scdc_helper.c > index df878aad4a36..8403f2390ab6 100644 > --- a/drivers/gpu/drm/display/drm_scdc_helper.c > +++ b/drivers/gpu/drm/display/drm_scdc_helper.c > @@ -67,8 +67,8 @@ > * Returns: > * 0 on success, negative error code on failure. > */ > -ssize_t drm_scdc_read(struct i2c_adapter *adapter, u8 offset, void *buffer, > - size_t size) > +int drm_scdc_read(struct i2c_adapter *adapter, u8 offset, void *buffer, > + size_t size) > { > int ret; > struct i2c_msg msgs[2] = { > @@ -107,8 +107,8 @@ EXPORT_SYMBOL(drm_scdc_read); > * Returns: > * 0 on success, negative error code on failure. > */ > -ssize_t drm_scdc_write(struct i2c_adapter *adapter, u8 offset, > - const void *buffer, size_t size) > +int drm_scdc_write(struct i2c_adapter *adapter, u8 offset, const void *buffer, > + size_t size) > { > struct i2c_msg msg = { > .addr = SCDC_I2C_SLAVE_ADDRESS, > diff --git a/include/drm/display/drm_scdc_helper.h b/include/drm/display/drm_scdc_helper.h > index 34600476a1b9..e9ccaeba56dd 100644 > --- a/include/drm/display/drm_scdc_helper.h > +++ b/include/drm/display/drm_scdc_helper.h > @@ -31,10 +31,10 @@ > struct drm_connector; > struct i2c_adapter; > > -ssize_t drm_scdc_read(struct i2c_adapter *adapter, u8 offset, void *buffer, > - size_t size); > -ssize_t drm_scdc_write(struct i2c_adapter *adapter, u8 offset, > - const void *buffer, size_t size); > +int drm_scdc_read(struct i2c_adapter *adapter, u8 offset, void *buffer, > + size_t size); > +int drm_scdc_write(struct i2c_adapter *adapter, u8 offset, const void *buffer, > + size_t size); > > /** > * drm_scdc_readb - read a single byte from SCDC >