[PATCH v2 05/15] drm/fbconv: Add DRM <-> fbdev pixel-format conversion

[Thomas Zimmermann]

Hi

Am 14.10.19 um 22:30 schrieb Sam Ravnborg:
> Hi Thomas.
> 
> On Mon, Oct 14, 2019 at 04:04:06PM +0200, Thomas Zimmermann wrote:
>> DRM uses FOURCC constants to describe pixel formats, fbdev uses a
>> per-component bitfield structure. The functions in this patch convert
>> between the two.
>>
> 
> A few nits below.
> 
> 
>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>> ---
>>   drivers/gpu/drm/drm_fbconv_helper.c | 435 ++++++++++++++++++++++++++++
>>   include/drm/drm_fbconv_helper.h     |  23 ++
>>   2 files changed, 458 insertions(+)
>>   create mode 100644 include/drm/drm_fbconv_helper.h
>>
>> diff --git a/drivers/gpu/drm/drm_fbconv_helper.c b/drivers/gpu/drm/drm_fbconv_helper.c
>> index 0cb46d2c98c3..af45358a156a 100644
>> --- a/drivers/gpu/drm/drm_fbconv_helper.c
>> +++ b/drivers/gpu/drm/drm_fbconv_helper.c
>> @@ -1 +1,436 @@
>>   // SPDX-License-Identifier: GPL-2.0-or-later
>> +
>> +#include <asm/byteorder.h>
>> +
>> +#include <linux/fb.h>
> 
> <asm/*> after <linux/*>
> So we in this way pick the more general include file first.

Ok.

>> +
>> +struct format_map {
>> +	bool (*is_format)(const struct fb_var_screeninfo *fb_var);
>> +	uint32_t format;
>> +};
> We are in the kernel - where I think u32 is preferred over the longer
> uint32_t.
> If I grep in drm/* then they seems be be equally popular, so feel free
> to ignore this comment.

I generally use types that are used by related interfaces. Here it's 
uint32_t because most other places use uint32_t for storing DRM_FORMAT 
constants.

> 
>> +static void set_fb_bitfield(struct fb_bitfield *bits, __u32 offset,
>> +			    __u32 length)
> 
> This is not uapi - so u32 is preferred.

Same as above. The __u32 comes from the fb_bitfield structure.

Best regards
Thomas

> Both comments apply to the whole file.
> 
> I did not see that this was wired into the kernel-doc in Documentation/
> but maybe I just missed it.
> 
> With my comments considered you can add:
> Acked-by: Sam Ravnborg <sam at ravnborg.org>
> 
> All code looks sane, but as I have not grasped the bigger picture
> this can hardly be a review.
> 
> 	Sam
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-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)