Hi Am 02.05.23 um 21:54 schrieb Sam Ravnborg:
Hi Thomas, On Tue, May 02, 2023 at 03:02:21PM +0200, Thomas Zimmermann wrote:Fbdev's main header file, <linux/fb.h>, includes <asm/io.h> to get declarations for I/O helper functions. From these declarations, it later defines framebuffer I/O helpers, such as fb_{read,write}[bwlq]() or fb_memset(). The framebuffer I/O helpers depend on the system architecture and will therefore be moved into <asm/fb.h>. Prepare this change by first adding an include statement for <linux/io.h> to <asm-generic/fb.h>. Include <asm/fb.h> in all source files that use the framebuffer I/O helpers, so that they still get the necessary I/O functions....diff --git a/drivers/video/fbdev/arkfb.c b/drivers/video/fbdev/arkfb.c index 60a96fdb5dd8..fd38e8a073b8 100644 --- a/drivers/video/fbdev/arkfb.c +++ b/drivers/video/fbdev/arkfb.c @@ -27,6 +27,8 @@ #include <linux/console.h> /* Why should fb driver call console functions? because console_lock() */ #include <video/vga.h>+#include <asm/fb.h>When we have a header like linux/fb.h - it is my understanding that it is preferred to include that file, and not the asm/fb.h variant. This is assuming the linux/fb.h contains the generic stuff, and includes asm/fb.h for the architecture specific parts. So drivers will include linux/fb.h and then they automatically get the architecture specific parts from asm/fb.h. In other words, drivers are not supposed to include asm/fb.h, if linux.fb.h exists - and linux/fb.h shall include the asm/fb.h. If the above holds true, then it is wrong and not needed to add asm/fb.h as seen above. There are countless examples where the above are not followed, but to my best understanding the above it the preferred way to do it.
Where did youher this? I only know about this in the case of asm/io.h vs. linux/io.h.
If that's the case, we should put those helpers into a new header file, because one of the motivations here is to remove <asm/io.h> from <linux/fb.h>.
Best regards Thomas
Sam
-- 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)
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