[PATCH 03/25] drm/fb_helper: Create wrappers for fb_sys_read/write funcs

[Archit Taneja]

On 07/13/2015 01:01 PM, Daniel Vetter wrote:
> On Mon, Jul 13, 2015 at 12:07:59PM +0530, Archit Taneja wrote:
>> Some drm drivers populate their fb_ops with fb_sys_read/write fb sysfs
>> ops.
>>
>> Create a drm_fb_helper function  that wraps around these calls.
>>
>> This is part of an effort to prevent drm drivers from calling fbdev
>> functions directly, in order to make fbdev emulation a top level drm
>> option.
>>
>> Signed-off-by: Archit Taneja <architt at codeaurora.org>
>> ---
>>   drivers/gpu/drm/Kconfig         |  1 +
>>   drivers/gpu/drm/drm_fb_helper.c | 20 ++++++++++++++++++++
>>   include/drm/drm_fb_helper.h     |  5 +++++
>>   3 files changed, 26 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>> index a66ac44..b284cdc 100644
>> --- a/drivers/gpu/drm/Kconfig
>> +++ b/drivers/gpu/drm/Kconfig
>> @@ -37,6 +37,7 @@ config DRM_KMS_FB_HELPER
>>   	select FB
>>   	select FRAMEBUFFER_CONSOLE if !EXPERT
>>   	select FRAMEBUFFER_CONSOLE_DETECT_PRIMARY if FRAMEBUFFER_CONSOLE
>> +	select FB_SYS_FOPS
>>   	help
>>   	  FBDEV helpers for KMS drivers.
>>
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>> index 742377d..795547e 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -744,6 +744,26 @@ void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
>>   }
>>   EXPORT_SYMBOL(drm_fb_helper_unlink_fbi);
>>
>> +ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
>> +			size_t count, loff_t *ppos)
>> +{
>> +	if (info)
>
> I think this check here can never fail (if there's no fbdev you can't call
> this function), I don't think we need it. Even for drivers which call this
> themselves (like qxl/udl) they only call it from fbdev code.

That's a good point. I'll remove the 'if (info)' check.

qxl/udl don't seem to call the fb sysfs funcs. So I think it's okay.

Archit

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