Hi Javier
Am 04.09.23 um 14:59 schrieb Javier Martinez Canillas:
Thomas Zimmermann [off-list ref] writes:
Hello Thomas,
quoted
Generate callback functions for struct fb_ops with the fbdev macro
FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(). Initialize struct fb_ops to
the generated functions with fbdev initializer macros.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Steve Glendinning <steve.glendinning@shawell.net>
---
The patch looks good to me, but I've a question below.
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
quoted
drivers/video/fbdev/smscufx.c | 85 +++++++++--------------------------
1 file changed, 22 insertions(+), 63 deletions(-)
diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c
[...]
quoted
static const struct fb_ops ufx_ops = {
.owner = THIS_MODULE,
- .fb_read = fb_sys_read,
- .fb_write = ufx_ops_write,
+ __FB_DEFAULT_DEFERRED_OPS_RDWR(ufx_ops),
.fb_setcolreg = ufx_ops_setcolreg,
- .fb_fillrect = ufx_ops_fillrect,
- .fb_copyarea = ufx_ops_copyarea,
- .fb_imageblit = ufx_ops_imageblit,
+ __FB_DEFAULT_DEFERRED_OPS_DRAW(ufx_ops),
.fb_mmap = ufx_ops_mmap,
There are no generated functions for .fb_mmap, I wonder what's the value
of __FB_DEFAULT_DEFERRED_OPS_MMAP() ? Maybe just removing that macro and
setting .fb_mmap = fb_deferred_io_mmap instead if there's no custom mmap
handler would be easier to read ?
At least two drivers could use __FB_DEFAULT_DEFERRED_OPS_MMAP: picolcd-fb and hyperv_fb. At some point, we might want to set/clear fb_mmap depending on some Kconfig value. Having __FB_DEFAULT_DEFERRED_OPS_MMAP might be helpful then.
Alternatively, __FB_DEFAULT_DEFERRED_OPS_MMAP() could still be left but
not taking a __prefix argument since that is not used anyways ?
The driver optionally provides mmap without deferred I/O, hence the mmap function. That makes no sense, as these writes to the buffer would never make it to the device memory. But I didn't want to remove the code either. So I just left the existing function as-is. Usually, the deferred-I/O mmap is called immediately. [1]
Best regards
Thomas
[1] https://elixir.bootlin.com/linux/v6.5.1/source/drivers/video/fbdev/smscufx.c#L784
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
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