* fb_write missing in skeleton
@ 2016-02-03 20:54 Ran Shalit
2016-02-04 8:16 ` Geert Uytterhoeven
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Ran Shalit @ 2016-02-03 20:54 UTC (permalink / raw)
To: linux-fbdev
Hello,
Is there any reason why fb_write is missing in skeletonfb.c ?
Isn't it required ?
Thank you,
Ran
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: fb_write missing in skeleton
2016-02-03 20:54 fb_write missing in skeleton Ran Shalit
@ 2016-02-04 8:16 ` Geert Uytterhoeven
2016-02-04 9:22 ` Ran Shalit
2016-02-04 9:34 ` Geert Uytterhoeven
2 siblings, 0 replies; 4+ messages in thread
From: Geert Uytterhoeven @ 2016-02-04 8:16 UTC (permalink / raw)
To: linux-fbdev
Hi Ran,
On Wed, Feb 3, 2016 at 9:54 PM, Ran Shalit <ranshalit@gmail.com> wrote:
> Is there any reason why fb_write is missing in skeletonfb.c ?
> Isn't it required ?
No, it's not required, cfr. the comments in include/linux/fb.h:
/* For framebuffers with strange non linear layouts or that do not
* work with normal memory mapped access
*/
ssize_t (*fb_read)(struct fb_info *info, char __user *buf,
size_t count, loff_t *ppos);
ssize_t (*fb_write)(struct fb_info *info, const char __user *buf,
size_t count, loff_t *ppos);
If not implemented, drivers/video/fbdev/core/fbmem.c:fb_write() will use
normal memory mapped access.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: fb_write missing in skeleton
2016-02-03 20:54 fb_write missing in skeleton Ran Shalit
2016-02-04 8:16 ` Geert Uytterhoeven
@ 2016-02-04 9:22 ` Ran Shalit
2016-02-04 9:34 ` Geert Uytterhoeven
2 siblings, 0 replies; 4+ messages in thread
From: Ran Shalit @ 2016-02-04 9:22 UTC (permalink / raw)
To: linux-fbdev
On Thu, Feb 4, 2016 at 10:16 AM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> Hi Ran,
>
> On Wed, Feb 3, 2016 at 9:54 PM, Ran Shalit <ranshalit@gmail.com> wrote:
>> Is there any reason why fb_write is missing in skeletonfb.c ?
>> Isn't it required ?
>
> No, it's not required, cfr. the comments in include/linux/fb.h:
>
> /* For framebuffers with strange non linear layouts or that do not
> * work with normal memory mapped access
> */
> ssize_t (*fb_read)(struct fb_info *info, char __user *buf,
> size_t count, loff_t *ppos);
> ssize_t (*fb_write)(struct fb_info *info, const char __user *buf,
> size_t count, loff_t *ppos);
>
> If not implemented, drivers/video/fbdev/core/fbmem.c:fb_write() will use
> normal memory mapped access.
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
Thanks Geert !
But When we do:
> cp mybitmap > /dev/fb0
Which method is called (isn't fb_write is called) ?
Is there a readme/tutorial which list the relation between userspace
operations (read/write/ioctl etc) to framebuffer drivers callbacks ?
I couldn't find any.
Best Regards,
Ran
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: fb_write missing in skeleton
2016-02-03 20:54 fb_write missing in skeleton Ran Shalit
2016-02-04 8:16 ` Geert Uytterhoeven
2016-02-04 9:22 ` Ran Shalit
@ 2016-02-04 9:34 ` Geert Uytterhoeven
2 siblings, 0 replies; 4+ messages in thread
From: Geert Uytterhoeven @ 2016-02-04 9:34 UTC (permalink / raw)
To: linux-fbdev
Hi Ran,
On Thu, Feb 4, 2016 at 10:22 AM, Ran Shalit <ranshalit@gmail.com> wrote:
> On Thu, Feb 4, 2016 at 10:16 AM, Geert Uytterhoeven
> <geert@linux-m68k.org> wrote:
>> On Wed, Feb 3, 2016 at 9:54 PM, Ran Shalit <ranshalit@gmail.com> wrote:
>>> Is there any reason why fb_write is missing in skeletonfb.c ?
>>> Isn't it required ?
>>
>> No, it's not required, cfr. the comments in include/linux/fb.h:
>>
>> /* For framebuffers with strange non linear layouts or that do not
>> * work with normal memory mapped access
>> */
>> ssize_t (*fb_read)(struct fb_info *info, char __user *buf,
>> size_t count, loff_t *ppos);
>> ssize_t (*fb_write)(struct fb_info *info, const char __user *buf,
>> size_t count, loff_t *ppos);
>>
>> If not implemented, drivers/video/fbdev/core/fbmem.c:fb_write() will use
>> normal memory mapped access.
> But When we do:
> > cp mybitmap > /dev/fb0
> Which method is called (isn't fb_write is called) ?
drivers/video/fbdev/core/fbmem.c:fb_write()
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-02-03 20:54 fb_write missing in skeleton Ran Shalit
2016-02-04 8:16 ` Geert Uytterhoeven
2016-02-04 9:22 ` Ran Shalit
2016-02-04 9:34 ` Geert Uytterhoeven
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