linux-kernel - Re: [PATCH v2 2/2] drm/bridge/synopsys: dsi: Fix dsi_host

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180126004628.fbrady7twf7ys2qx@ban.mtv.corp.google.com>
Date:   Thu, 25 Jan 2018 16:46:29 -0800
From:   Brian Norris <briannorris@...omium.org>
To:     Philippe Cornu <philippe.cornu@...com>
Cc:     Archit Taneja <architt@...eaurora.org>,
        Andrzej Hajda <a.hajda@...sung.com>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        David Airlie <airlied@...ux.ie>,
        Benjamin Gaignard <benjamin.gaignard@...aro.org>,
        Bhumika Goyal <bhumirks@...il.com>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Sandy Huang <hjc@...k-chips.com>,
        Heiko Stubner <heiko@...ech.de>,
        linux-arm-kernel@...ts.infradead.org,
        linux-rockchip@...ts.infradead.org,
        Yannick Fertre <yannick.fertre@...com>,
        Vincent Abriou <vincent.abriou@...com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Ludovic Barre <ludovic.barre@...com>,
        Mickael Reulier <mickael.reulier@...com>
Subject: Re: [PATCH v2 2/2] drm/bridge/synopsys: dsi: Fix dsi_host_transfer()
 return value

On Thu, Jan 25, 2018 at 11:38:00AM +0100, Philippe Cornu wrote:
> The dw_mipi_dsi_host_transfer() must return the number of
> bytes transmitted/received on success instead of 0.
> Note: As the read feature is not implemented, only the
> transmitted number of bytes is returned for the moment.
> 
> Signed-off-by: Philippe Cornu <philippe.cornu@...com>

Assuming we're going with the current documented semantics (where we
return # of TX bytes for writes), then:

Reviewed-by: Brian Norris <briannorris@...omium.org>

I believe Archit was suggesting maybe changing that sometime, but that's
no excuse for not matching documentation now.

> ---
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 72ecaeb40822..090bf62d1ea8 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -419,7 +419,16 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
>  
>  	dw_mipi_message_config(dsi, msg);
>  
> -	return dw_mipi_dsi_write(dsi, &packet);
> +	ret = dw_mipi_dsi_write(dsi, &packet);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * TODO Only transmitted size is returned as actual driver does
> +	 * not support dcs/generic reads. Please update return value when
> +	 * delivering the read feature.
> +	 */
> +	return packet.size;

You're really holding my hand here, I see :) Thanks I guess.

>  }
>  
>  static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {
> -- 
> 2.15.1
>