[v2,11/12] drm/fbdev-generic: Implement dedicated fbdev I/O helpers

Thomas Zimmermann tzimmermann at suse.de
Wed May 17 00:07:04 PDT 2023


Hi

Am 17.05.23 um 03:58 schrieb Sui Jingfeng:
> Hi, Thomas
> 
> 
> After apply your patch set, the kernel with 
> arch/loongarch/configs/loongson3_defconfig
> 
> can not finish compile anymore.  gcc complains:
> 
> 
>    AR      drivers/gpu/built-in.a
>    AR      drivers/built-in.a
>    AR      built-in.a
>    AR      vmlinux.a
>    LD      vmlinux.o
>    OBJCOPY modules.builtin.modinfo
>    GEN     modules.builtin
>    GEN     .vmlinux.objs
>    MODPOST Module.symvers
> ERROR: modpost: "fb_sys_write" [drivers/gpu/drm/drm_kms_helper.ko] 
> undefined!
> ERROR: modpost: "sys_imageblit" [drivers/gpu/drm/drm_kms_helper.ko] 
> undefined!
> ERROR: modpost: "sys_fillrect" [drivers/gpu/drm/drm_kms_helper.ko] 
> undefined!
> ERROR: modpost: "sys_copyarea" [drivers/gpu/drm/drm_kms_helper.ko] 
> undefined!
> ERROR: modpost: "fb_sys_read" [drivers/gpu/drm/drm_kms_helper.ko] 
> undefined!
> make[1]: *** [scripts/Makefile.modpost:136: Module.symvers] Error 1
> make: *** [Makefile:1978: modpost] Error 2

Thanks for reporting this problem. I found that it's caused by a typo in 
the very first patch 1/7, where these helpers are not selected 
correctly. Will be fixed in the next round.

Best regards
Thomas

> 
> 
> On 2023/5/15 17:40, Thomas Zimmermann wrote:
>> Implement dedicated fbdev helpers for framebuffer I/O instead
>> of using DRM's helpers. Fbdev-generic was the only caller of the
>> DRM helpers, so remove them from the helper module.
>>
>> v2:
>>     * use FB_SYS_HELPERS_DEFERRED option
>>
>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>> ---
>>   drivers/gpu/drm/Kconfig             |   6 +-
>>   drivers/gpu/drm/drm_fb_helper.c     | 107 ----------------------------
>>   drivers/gpu/drm/drm_fbdev_generic.c |  47 ++++++++++--
>>   include/drm/drm_fb_helper.h         |  41 -----------
>>   4 files changed, 43 insertions(+), 158 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>> index 77fb10ddd8a2..92a782827b7b 100644
>> --- a/drivers/gpu/drm/Kconfig
>> +++ b/drivers/gpu/drm/Kconfig
>> @@ -95,6 +95,7 @@ config DRM_KUNIT_TEST
>>   config DRM_KMS_HELPER
>>       tristate
>>       depends on DRM
>> +    select FB_SYS_HELPERS_DEFERRED if DRM_FBDEV_EMULATION
> 
> Here, select FB_SYS_HELPERS helps resolve the above issue mentioned.
> 
>>       help
>>         CRTC helpers for KMS drivers.
>> @@ -135,11 +136,6 @@ config DRM_FBDEV_EMULATION
>>       select FB_CFB_FILLRECT
>>       select FB_CFB_COPYAREA
>>       select FB_CFB_IMAGEBLIT
>> -    select FB_DEFERRED_IO
>> -    select FB_SYS_FOPS
>> -    select FB_SYS_FILLRECT
>> -    select FB_SYS_COPYAREA
>> -    select FB_SYS_IMAGEBLIT
>>       select FRAMEBUFFER_CONSOLE if !EXPERT
>>       select FRAMEBUFFER_CONSOLE_DETECT_PRIMARY if FRAMEBUFFER_CONSOLE
>>       default y
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c 
>> b/drivers/gpu/drm/drm_fb_helper.c
>> index 8724e08c518b..ba0a808f14ee 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -729,113 +729,6 @@ void drm_fb_helper_deferred_io(struct fb_info 
>> *info, struct list_head *pagerefli
>>   }
>>   EXPORT_SYMBOL(drm_fb_helper_deferred_io);
>> -/**
>> - * drm_fb_helper_sys_read - Implements struct &fb_ops.fb_read for 
>> system memory
>> - * @info: fb_info struct pointer
>> - * @buf: userspace buffer to read from framebuffer memory
>> - * @count: number of bytes to read from framebuffer memory
>> - * @ppos: read offset within framebuffer memory
>> - *
>> - * Returns:
>> - * The number of bytes read on success, or an error code otherwise.
>> - */
>> -ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
>> -                   size_t count, loff_t *ppos)
>> -{
>> -    return fb_sys_read(info, buf, count, ppos);
>> -}
>> -EXPORT_SYMBOL(drm_fb_helper_sys_read);
>> -
>> -/**
>> - * drm_fb_helper_sys_write - Implements struct &fb_ops.fb_write for 
>> system memory
>> - * @info: fb_info struct pointer
>> - * @buf: userspace buffer to write to framebuffer memory
>> - * @count: number of bytes to write to framebuffer memory
>> - * @ppos: write offset within framebuffer memory
>> - *
>> - * Returns:
>> - * The number of bytes written on success, or an error code otherwise.
>> - */
>> -ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char 
>> __user *buf,
>> -                size_t count, loff_t *ppos)
>> -{
>> -    struct drm_fb_helper *helper = info->par;
>> -    loff_t pos = *ppos;
>> -    ssize_t ret;
>> -    struct drm_rect damage_area;
>> -
>> -    ret = fb_sys_write(info, buf, count, ppos);
>> -    if (ret <= 0)
>> -        return ret;
>> -
>> -    if (helper->funcs->fb_dirty) {
>> -        drm_fb_helper_memory_range_to_clip(info, pos, ret, 
>> &damage_area);
>> -        drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
>> -                     drm_rect_width(&damage_area),
>> -                     drm_rect_height(&damage_area));
>> -    }
>> -
>> -    return ret;
>> -}
>> -EXPORT_SYMBOL(drm_fb_helper_sys_write);
>> -
>> -/**
>> - * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
>> - * @info: fbdev registered by the helper
>> - * @rect: info about rectangle to fill
>> - *
>> - * A wrapper around sys_fillrect implemented by fbdev core
>> - */
>> -void drm_fb_helper_sys_fillrect(struct fb_info *info,
>> -                const struct fb_fillrect *rect)
>> -{
>> -    struct drm_fb_helper *helper = info->par;
>> -
>> -    sys_fillrect(info, rect);
>> -
>> -    if (helper->funcs->fb_dirty)
>> -        drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, 
>> rect->height);
>> -}
>> -EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
>> -
>> -/**
>> - * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
>> - * @info: fbdev registered by the helper
>> - * @area: info about area to copy
>> - *
>> - * A wrapper around sys_copyarea implemented by fbdev core
>> - */
>> -void drm_fb_helper_sys_copyarea(struct fb_info *info,
>> -                const struct fb_copyarea *area)
>> -{
>> -    struct drm_fb_helper *helper = info->par;
>> -
>> -    sys_copyarea(info, area);
>> -
>> -    if (helper->funcs->fb_dirty)
>> -        drm_fb_helper_damage(helper, area->dx, area->dy, area->width, 
>> area->height);
>> -}
>> -EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
>> -
>> -/**
>> - * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
>> - * @info: fbdev registered by the helper
>> - * @image: info about image to blit
>> - *
>> - * A wrapper around sys_imageblit implemented by fbdev core
>> - */
>> -void drm_fb_helper_sys_imageblit(struct fb_info *info,
>> -                 const struct fb_image *image)
>> -{
>> -    struct drm_fb_helper *helper = info->par;
>> -
>> -    sys_imageblit(info, image);
>> -
>> -    if (helper->funcs->fb_dirty)
>> -        drm_fb_helper_damage(helper, image->dx, image->dy, 
>> image->width, image->height);
>> -}
>> -EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
>> -
>>   /**
>>    * drm_fb_helper_cfb_read - Implements struct &fb_ops.fb_read for 
>> I/O memory
>>    * @info: fb_info struct pointer
>> diff --git a/drivers/gpu/drm/drm_fbdev_generic.c 
>> b/drivers/gpu/drm/drm_fbdev_generic.c
>> index 8e5148bf40bb..f53fc49e34a4 100644
>> --- a/drivers/gpu/drm/drm_fbdev_generic.c
>> +++ b/drivers/gpu/drm/drm_fbdev_generic.c
>> @@ -34,6 +34,43 @@ static int drm_fbdev_generic_fb_release(struct 
>> fb_info *info, int user)
>>       return 0;
>>   }
>> +static ssize_t drm_fbdev_generic_fb_write(struct fb_info *info, const 
>> char __user *buf,
>> +                      size_t count, loff_t *ppos)
>> +{
>> +    struct drm_fb_helper *helper = info->par;
>> +    loff_t pos = *ppos;
>> +    ssize_t ret;
>> +
>> +    ret = fb_sys_write(info, buf, count, ppos);
>> +    if (ret > 0)
>> +        drm_fb_helper_damage_range(helper, pos, ret);
>> +    return ret;
>> +}
>> +
>> +static void drm_fbdev_generic_fb_fillrect(struct fb_info *info, const 
>> struct fb_fillrect *rect)
>> +{
>> +    struct drm_fb_helper *helper = info->par;
>> +
>> +    sys_fillrect(info, rect);
>> +    drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, 
>> rect->height);
>> +}
>> +
>> +static void drm_fbdev_generic_fb_copyarea(struct fb_info *info, const 
>> struct fb_copyarea *area)
>> +{
>> +    struct drm_fb_helper *helper = info->par;
>> +
>> +    sys_copyarea(info, area);
>> +    drm_fb_helper_damage(helper, area->dx, area->dy, area->width, 
>> area->height);
>> +}
>> +
>> +static void drm_fbdev_generic_fb_imageblit(struct fb_info *info, 
>> const struct fb_image *image)
>> +{
>> +    struct drm_fb_helper *helper = info->par;
>> +
>> +    sys_imageblit(info, image);
>> +    drm_fb_helper_damage(helper, image->dx, image->dy, image->width, 
>> image->height);
>> +}
>> +
>>   static void drm_fbdev_generic_fb_destroy(struct fb_info *info)
>>   {
>>       struct drm_fb_helper *fb_helper = info->par;
>> @@ -56,12 +93,12 @@ static const struct fb_ops 
>> drm_fbdev_generic_fb_ops = {
>>       .owner        = THIS_MODULE,
>>       .fb_open    = drm_fbdev_generic_fb_open,
>>       .fb_release    = drm_fbdev_generic_fb_release,
>> -    .fb_read    = drm_fb_helper_sys_read,
>> -    .fb_write    = drm_fb_helper_sys_write,
>> +    .fb_read    = fb_sys_read,
>> +    .fb_write    = drm_fbdev_generic_fb_write,
>>       DRM_FB_HELPER_DEFAULT_OPS,
>> -    .fb_fillrect    = drm_fb_helper_sys_fillrect,
>> -    .fb_copyarea    = drm_fb_helper_sys_copyarea,
>> -    .fb_imageblit    = drm_fb_helper_sys_imageblit,
>> +    .fb_fillrect    = drm_fbdev_generic_fb_fillrect,
>> +    .fb_copyarea    = drm_fbdev_generic_fb_copyarea,
>> +    .fb_imageblit    = drm_fbdev_generic_fb_imageblit,
>>       .fb_mmap    = fb_deferred_io_mmap,
>>       .fb_destroy    = drm_fbdev_generic_fb_destroy,
>>   };
>> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
>> index 80c402f4e379..e3240d749a43 100644
>> --- a/include/drm/drm_fb_helper.h
>> +++ b/include/drm/drm_fb_helper.h
>> @@ -259,18 +259,6 @@ void drm_fb_helper_damage_range(struct 
>> drm_fb_helper *helper, off_t off, size_t
>>   void drm_fb_helper_deferred_io(struct fb_info *info, struct 
>> list_head *pagereflist);
>> -ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
>> -                   size_t count, loff_t *ppos);
>> -ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char 
>> __user *buf,
>> -                size_t count, loff_t *ppos);
>> -
>> -void drm_fb_helper_sys_fillrect(struct fb_info *info,
>> -                const struct fb_fillrect *rect);
>> -void drm_fb_helper_sys_copyarea(struct fb_info *info,
>> -                const struct fb_copyarea *area);
>> -void drm_fb_helper_sys_imageblit(struct fb_info *info,
>> -                 const struct fb_image *image);
>> -
>>   ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
>>                      size_t count, loff_t *ppos);
>>   ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char 
>> __user *buf,
>> @@ -398,35 +386,6 @@ static inline int drm_fb_helper_defio_init(struct 
>> drm_fb_helper *fb_helper)
>>       return -ENODEV;
>>   }
>> -static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
>> -                         char __user *buf, size_t count,
>> -                         loff_t *ppos)
>> -{
>> -    return -ENODEV;
>> -}
>> -
>> -static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
>> -                          const char __user *buf,
>> -                          size_t count, loff_t *ppos)
>> -{
>> -    return -ENODEV;
>> -}
>> -
>> -static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
>> -                          const struct fb_fillrect *rect)
>> -{
>> -}
>> -
>> -static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
>> -                          const struct fb_copyarea *area)
>> -{
>> -}
>> -
>> -static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
>> -                           const struct fb_image *image)
>> -{
>> -}
>> -
>>   static inline ssize_t drm_fb_helper_cfb_read(struct fb_info *info, 
>> char __user *buf,
>>                            size_t count, loff_t *ppos)
>>   {

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 840 bytes
Desc: OpenPGP digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20230517/74267480/attachment.sig>


More information about the linux-arm-kernel mailing list