| 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
| ||
|
Message-ID: <0c7d4909-b926-1370-2847-c801172248c9@st.com>
Date: Thu, 21 Dec 2017 14:59:50 +0000
From: Philippe CORNU <philippe.cornu@...com>
To: Nickey Yang <nickey.yang@...k-chips.com>,
"robh+dt@...nel.org" <robh+dt@...nel.org>,
"heiko@...ech.de" <heiko@...ech.de>,
"mark.rutland@....com" <mark.rutland@....com>,
"airlied@...ux.ie" <airlied@...ux.ie>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
"linux-rockchip@...ts.infradead.org"
<linux-rockchip@...ts.infradead.org>,
"laurent.pinchart@...asonboard.com"
<laurent.pinchart@...asonboard.com>,
"seanpaul@...omium.org" <seanpaul@...omium.org>,
"briannorris@...omium.org" <briannorris@...omium.org>,
"mka@...omium.org" <mka@...omium.org>,
"hoegsberg@...il.com" <hoegsberg@...il.com>,
"architt@...eaurora.org" <architt@...eaurora.org>,
Yannick FERTRE <yannick.fertre@...com>,
"hl@...k-chips.com" <hl@...k-chips.com>,
"zyw@...k-chips.com" <zyw@...k-chips.com>,
"xbl@...k-chips.com" <xbl@...k-chips.com>
Subject: Re: [PATCH v7 1/3] drm/bridge/synopsys: dsi: stop clobbering drvdata
Hi Nickey,
On 12/12/2017 02:10 AM, Nickey Yang wrote:
> From: Brian Norris <briannorris@...omium.org>
>
> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> parent driver might need to own this. Instead, let's return our
> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
>
> Signed-off-by: Brian Norris <briannorris@...omium.org>
> Signed-off-by: Nickey Yang <nickey.yang@...k-chips.com>
> Link:https://patchwork.kernel.org/patch/10078493/
>
> ---
> Changes
>
> v4:
> - Add From tag,update subject line
> - keep patch "drm/stm: dsi: Adjust dw_mipi_dsi_probe and remove"
> in this piece together.
>
> v5:
> - remove Review & Ack tag
> - fix remove() directly referencing the static
> dw_mipi_dsi_stm_plat_data struct.
>
> v7:
> - add missing platform_set_drvdata in stm part.
>
> drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++-----------------
> drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 12 ++++++---
> include/drm/bridge/dw_mipi_dsi.h | 17 ++++++++-----
> 3 files changed, 32 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index d9cca4f..c39c7dc 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -922,8 +922,6 @@ static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge)
> dsi->bridge.of_node = pdev->dev.of_node;
> #endif
>
> - dev_set_drvdata(dev, dsi);
> -
> return dsi;
> }
>
> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
> /*
> * Probe/remove API, used from platforms based on the DRM bridge API.
> */
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> - const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_probe(struct platform_device *pdev,
> + const struct dw_mipi_dsi_plat_data *plat_data)
> {
> - struct dw_mipi_dsi *dsi;
> -
> - dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> - if (IS_ERR(dsi))
> - return PTR_ERR(dsi);
> -
> - return 0;
> + return __dw_mipi_dsi_probe(pdev, plat_data);
> }
> EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>
> -void dw_mipi_dsi_remove(struct platform_device *pdev)
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
> {
> - struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
> -
> mipi_dsi_host_unregister(&dsi->dsi_host);
>
> __dw_mipi_dsi_remove(dsi);
> @@ -961,31 +952,30 @@ void dw_mipi_dsi_remove(struct platform_device *pdev)
> /*
> * Bind/unbind API, used from platforms based on the component framework.
> */
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> - const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> + const struct dw_mipi_dsi_plat_data *plat_data)
> {
> struct dw_mipi_dsi *dsi;
> int ret;
>
> dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> if (IS_ERR(dsi))
> - return PTR_ERR(dsi);
> + return dsi;
>
> ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
> if (ret) {
> - dw_mipi_dsi_remove(pdev);
> + dw_mipi_dsi_remove(dsi);
> DRM_ERROR("Failed to initialize bridge with drm\n");
> - return ret;
> + return ERR_PTR(ret);
> }
>
> - return 0;
> + return dsi;
> }
> EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>
> -void dw_mipi_dsi_unbind(struct device *dev)
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
> {
> - struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
> -
> __dw_mipi_dsi_remove(dsi);
> }
> EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index e5b6310..c1ed691 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -66,6 +66,7 @@ enum dsi_color {
> struct dw_mipi_dsi_stm {
> void __iomem *base;
> struct clk *pllref_clk;
> + struct dw_mipi_dsi *dmd;
> };
>
> static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
> @@ -290,6 +291,8 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
> if (!dsi)
> return -ENOMEM;
>
> + platform_set_drvdata(pdev, dsi);
> +
Why don't you simply use the original patch from Brian.
With your last update, platform_set_drvdata() is called early during the
stm_probe() and this is not the "classic" way: most of the time we
prefer calling platform_set_drvdata() at the end of the probe (or as
close as possible of the end of the probe). I took few minutes to look
into drm directory and it seems to be the classic way for most of the
drivers...
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!res) {
> DRM_ERROR("Unable to get resource\n");
> @@ -318,10 +321,11 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
> dw_mipi_dsi_stm_plat_data.base = dsi->base;
> dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>
> - ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> - if (ret) {
> + dsi->dmd = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> + if (IS_ERR(dsi->dmd)) {
> DRM_ERROR("Failed to initialize mipi dsi host\n");
> clk_disable_unprepare(dsi->pllref_clk);
> + return PTR_ERR(dsi->dmd);
> }
>
> return ret;
Moreover, I do prefer the "return 0;" from the Brian original version
because "ret" here is far from its usage (from clk_prepare_enable())
with this new patch.
So, once again, I really prefer the Brian original version, on which you
already got my Tested-By & Acked-by.
Is there any reason why you did not use the original patch?
Many thanks,
Philippe :-)
Note: I will be ooo next 2 weeks.
> @@ -329,10 +333,10 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>
> static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
> {
> - struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> + struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>
> clk_disable_unprepare(dsi->pllref_clk);
> - dw_mipi_dsi_remove(pdev);
> + dw_mipi_dsi_remove(dsi->dmd);
>
> return 0;
> }
> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> index 9b30fec..d9c6d54 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -10,6 +10,8 @@
> #ifndef __DW_MIPI_DSI__
> #define __DW_MIPI_DSI__
>
> +struct dw_mipi_dsi;
> +
> struct dw_mipi_dsi_phy_ops {
> int (*init)(void *priv_data);
> int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
> void *priv_data;
> };
>
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> - const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_remove(struct platform_device *pdev);
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> - const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_unbind(struct device *dev);
> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> + const struct dw_mipi_dsi_plat_data
> + *plat_data);
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
> + struct drm_encoder *encoder,
> + const struct dw_mipi_dsi_plat_data
> + *plat_data);
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>
> #endif /* __DW_MIPI_DSI__ */
>
Powered by blists - more mailing lists