2021-02-02 12:15:42

by Christoph Hellwig

[permalink] [raw]
Subject: [PATCH 02/13] drm: remove drm_fb_helper_modinit

drm_fb_helper_modinit has a lot of boilerplate for what is not very
simple functionality. Just open code it in the only caller using
IS_ENABLED and IS_MODULE, and skip the find_module check as a
request_module is harmless if the module is already loaded (and not
other caller has this find_module check either).

Signed-off-by: Christoph Hellwig <[email protected]>
---
drivers/gpu/drm/drm_crtc_helper_internal.h | 10 ---------
drivers/gpu/drm/drm_fb_helper.c | 21 ------------------
drivers/gpu/drm/drm_kms_helper_common.c | 25 +++++++++++-----------
3 files changed, 12 insertions(+), 44 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h b/drivers/gpu/drm/drm_crtc_helper_internal.h
index 25ce42e799952c..61e09f8a8d0ff0 100644
--- a/drivers/gpu/drm/drm_crtc_helper_internal.h
+++ b/drivers/gpu/drm/drm_crtc_helper_internal.h
@@ -32,16 +32,6 @@
#include <drm/drm_encoder.h>
#include <drm/drm_modes.h>

-/* drm_fb_helper.c */
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-int drm_fb_helper_modinit(void);
-#else
-static inline int drm_fb_helper_modinit(void)
-{
- return 0;
-}
-#endif
-
/* drm_dp_aux_dev.c */
#ifdef CONFIG_DRM_DP_AUX_CHARDEV
int drm_dp_aux_dev_init(void);
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 4b81195106875d..0b9f1ae1b7864c 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2499,24 +2499,3 @@ void drm_fbdev_generic_setup(struct drm_device *dev,
drm_client_register(&fb_helper->client);
}
EXPORT_SYMBOL(drm_fbdev_generic_setup);
-
-/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
- * but the module doesn't depend on any fb console symbols. At least
- * attempt to load fbcon to avoid leaving the system without a usable console.
- */
-int __init drm_fb_helper_modinit(void)
-{
-#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
- const char name[] = "fbcon";
- struct module *fbcon;
-
- mutex_lock(&module_mutex);
- fbcon = find_module(name);
- mutex_unlock(&module_mutex);
-
- if (!fbcon)
- request_module_nowait(name);
-#endif
- return 0;
-}
-EXPORT_SYMBOL(drm_fb_helper_modinit);
diff --git a/drivers/gpu/drm/drm_kms_helper_common.c b/drivers/gpu/drm/drm_kms_helper_common.c
index 221a8528c9937a..f933da1656eb52 100644
--- a/drivers/gpu/drm/drm_kms_helper_common.c
+++ b/drivers/gpu/drm/drm_kms_helper_common.c
@@ -64,19 +64,18 @@ MODULE_PARM_DESC(edid_firmware,

static int __init drm_kms_helper_init(void)
{
- int ret;
-
- /* Call init functions from specific kms helpers here */
- ret = drm_fb_helper_modinit();
- if (ret < 0)
- goto out;
-
- ret = drm_dp_aux_dev_init();
- if (ret < 0)
- goto out;
-
-out:
- return ret;
+ /*
+ * The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
+ * but the module doesn't depend on any fb console symbols. At least
+ * attempt to load fbcon to avoid leaving the system without a usable
+ * console.
+ */
+ if (IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION) &&
+ IS_MODULE(CONFIG_FRAMEBUFFER_CONSOLE) &&
+ !IS_ENABLED(CONFIG_EXPERT))
+ request_module_nowait("fbcon");
+
+ return drm_dp_aux_dev_init();
}

static void __exit drm_kms_helper_exit(void)
--
2.29.2


2021-02-03 10:37:09

by Daniel Vetter

[permalink] [raw]
Subject: Re: [PATCH 02/13] drm: remove drm_fb_helper_modinit

On Thu, Jan 28, 2021 at 07:14:10PM +0100, Christoph Hellwig wrote:
> drm_fb_helper_modinit has a lot of boilerplate for what is not very
> simple functionality. Just open code it in the only caller using
> IS_ENABLED and IS_MODULE, and skip the find_module check as a
> request_module is harmless if the module is already loaded (and not
> other caller has this find_module check either).
>
> Signed-off-by: Christoph Hellwig <[email protected]>

Hm I thought I've acked this one already somewhere for merging through
your tree.

Acked-by: Daniel Vetter <[email protected]>

> ---
> drivers/gpu/drm/drm_crtc_helper_internal.h | 10 ---------
> drivers/gpu/drm/drm_fb_helper.c | 21 ------------------
> drivers/gpu/drm/drm_kms_helper_common.c | 25 +++++++++++-----------
> 3 files changed, 12 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h b/drivers/gpu/drm/drm_crtc_helper_internal.h
> index 25ce42e799952c..61e09f8a8d0ff0 100644
> --- a/drivers/gpu/drm/drm_crtc_helper_internal.h
> +++ b/drivers/gpu/drm/drm_crtc_helper_internal.h
> @@ -32,16 +32,6 @@
> #include <drm/drm_encoder.h>
> #include <drm/drm_modes.h>
>
> -/* drm_fb_helper.c */
> -#ifdef CONFIG_DRM_FBDEV_EMULATION
> -int drm_fb_helper_modinit(void);
> -#else
> -static inline int drm_fb_helper_modinit(void)
> -{
> - return 0;
> -}
> -#endif
> -
> /* drm_dp_aux_dev.c */
> #ifdef CONFIG_DRM_DP_AUX_CHARDEV
> int drm_dp_aux_dev_init(void);
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 4b81195106875d..0b9f1ae1b7864c 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -2499,24 +2499,3 @@ void drm_fbdev_generic_setup(struct drm_device *dev,
> drm_client_register(&fb_helper->client);
> }
> EXPORT_SYMBOL(drm_fbdev_generic_setup);
> -
> -/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
> - * but the module doesn't depend on any fb console symbols. At least
> - * attempt to load fbcon to avoid leaving the system without a usable console.
> - */
> -int __init drm_fb_helper_modinit(void)
> -{
> -#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
> - const char name[] = "fbcon";
> - struct module *fbcon;
> -
> - mutex_lock(&module_mutex);
> - fbcon = find_module(name);
> - mutex_unlock(&module_mutex);
> -
> - if (!fbcon)
> - request_module_nowait(name);
> -#endif
> - return 0;
> -}
> -EXPORT_SYMBOL(drm_fb_helper_modinit);
> diff --git a/drivers/gpu/drm/drm_kms_helper_common.c b/drivers/gpu/drm/drm_kms_helper_common.c
> index 221a8528c9937a..f933da1656eb52 100644
> --- a/drivers/gpu/drm/drm_kms_helper_common.c
> +++ b/drivers/gpu/drm/drm_kms_helper_common.c
> @@ -64,19 +64,18 @@ MODULE_PARM_DESC(edid_firmware,
>
> static int __init drm_kms_helper_init(void)
> {
> - int ret;
> -
> - /* Call init functions from specific kms helpers here */
> - ret = drm_fb_helper_modinit();
> - if (ret < 0)
> - goto out;
> -
> - ret = drm_dp_aux_dev_init();
> - if (ret < 0)
> - goto out;
> -
> -out:
> - return ret;
> + /*
> + * The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
> + * but the module doesn't depend on any fb console symbols. At least
> + * attempt to load fbcon to avoid leaving the system without a usable
> + * console.
> + */
> + if (IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION) &&
> + IS_MODULE(CONFIG_FRAMEBUFFER_CONSOLE) &&
> + !IS_ENABLED(CONFIG_EXPERT))
> + request_module_nowait("fbcon");
> +
> + return drm_dp_aux_dev_init();
> }
>
> static void __exit drm_kms_helper_exit(void)
> --
> 2.29.2
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2021-02-03 10:53:18

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH 02/13] drm: remove drm_fb_helper_modinit

On Wed, Feb 03, 2021 at 11:34:50AM +0100, Daniel Vetter wrote:
> On Thu, Jan 28, 2021 at 07:14:10PM +0100, Christoph Hellwig wrote:
> > drm_fb_helper_modinit has a lot of boilerplate for what is not very
> > simple functionality. Just open code it in the only caller using
> > IS_ENABLED and IS_MODULE, and skip the find_module check as a
> > request_module is harmless if the module is already loaded (and not
> > other caller has this find_module check either).
> >
> > Signed-off-by: Christoph Hellwig <[email protected]>
>
> Hm I thought I've acked this one already somewhere for merging through
> your tree.
>
> Acked-by: Daniel Vetter <[email protected]>

The difference is that this new version loses the find_module entirely,
while the previous one replaced it with the module_loaded helper that
didn't make it to the second version of the series.