linux-kernel - Re: [Linux-stm32] [PATCH v8 08/10] drm: stm: dw-mipi-dsi: let the bridge handle the HW version check

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: <4acc09e8-0610-01f6-b18d-3ffc390c45a3@st.com>
Date:   Fri, 29 May 2020 15:45:44 +0000
From:   Philippe CORNU <philippe.cornu@...com>
To:     Adrian Ratiu <adrian.ratiu@...labora.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-rockchip@...ts.infradead.org" 
        <linux-rockchip@...ts.infradead.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>
CC:     Jernej Skrabec <jernej.skrabec@...l.net>,
        Heiko Stuebner <heiko@...ech.de>,
        Adrian Pop <pop.adrian61@...il.com>,
        Jonas Karlman <jonas@...boo.se>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        Andrzej Hajda <a.hajda@...sung.com>,
        "linux-imx@....com" <linux-imx@....com>,
        "kernel@...labora.com" <kernel@...labora.com>,
        "linux-stm32@...md-mailman.stormreply.com" 
        <linux-stm32@...md-mailman.stormreply.com>,
        Arnaud Ferraris <arnaud.ferraris@...labora.com>,
        Yannick FERTRE <yannick.fertre@...com>,
        Benjamin GAIGNARD <benjamin.gaignard@...com>
Subject: Re: [Linux-stm32] [PATCH v8 08/10] drm: stm: dw-mipi-dsi: let the
 bridge handle the HW version check

Hi Adrian,
and thank you very much for the patchset.
Thank you also for having tested it on STM32F769 and STM32MP1.
Sorry for the late response, Yannick and I will review it as soon as 
possible and we will keep you posted.
Note: Do not hesitate to put us in copy for the next version 
(philippe.cornu@...com, yannick.fertre@...com)
Regards,
Philippe :-)


On 4/27/20 10:19 AM, Adrian Ratiu wrote:
> The stm mipi-dsi platform driver added a version test in
> commit fa6251a747b7 ("drm/stm: dsi: check hardware version")
> so that HW revisions other than v1.3x get rejected. The rockchip
> driver had no such check and just assumed register layouts are
> v1.3x compatible.
> 
> Having such tests was a good idea because only v130/v131 layouts
> were supported at the time, however since adding multiple layout
> support in the bridge, the version is automatically checked for
> all drivers, compatible layouts get picked and unsupported HW is
> automatically rejected by the bridge, so there's no use keeping
> the test in the stm driver.
> 
> The main reason prompting this change is that the stm driver
> test immediately disabled the peripheral clock after reading
> the version, making the bridge read version 0x0 immediately
> after in its own probe(), so we move the clock disabling after
> the bridge does the version test.
> 
> Tested on STM32F769 and STM32MP1.
> 
> Cc: linux-stm32@...md-mailman.stormreply.com
> Reported-by: Adrian Pop <pop.adrian61@...il.com>
> Tested-by: Adrian Pop <pop.adrian61@...il.com>
> Tested-by: Arnaud Ferraris <arnaud.ferraris@...labora.com>
> Signed-off-by: Adrian Ratiu <adrian.ratiu@...labora.com>
> ---
> New in v6.
> ---
>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 12 +++---------
>   1 file changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index 2e1f2664495d0..7218e405d7e2b 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -402,15 +402,6 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   		goto err_dsi_probe;
>   	}
>   
> -	dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
> -	clk_disable_unprepare(pclk);
> -
> -	if (dsi->hw_version != HWVER_130 && dsi->hw_version != HWVER_131) {
> -		ret = -ENODEV;
> -		DRM_ERROR("bad dsi hardware version\n");
> -		goto err_dsi_probe;
> -	}
> -
>   	dw_mipi_dsi_stm_plat_data.base = dsi->base;
>   	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>   
> @@ -423,6 +414,9 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   		goto err_dsi_probe;
>   	}
>   
> +	dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
> +	clk_disable_unprepare(pclk);
> +
>   	return 0;
>   
>   err_dsi_probe:
>