Hi

On Thu, Jan 23, 2014 at 5:51 PM, Ingo Molnar [off-list ref] wrote:

Just a couple of small nits:

* David Herrmann [off-list ref] wrote:

quoted

--- a/arch/x86/kernel/sysfb.c
+++ b/arch/x86/kernel/sysfb.c

@@ -33,11 +33,76 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/mutex.h>
 #include <linux/platform_data/simplefb.h>
 #include <linux/platform_device.h>
 #include <linux/screen_info.h>
 #include <asm/sysfb.h>

+static DEFINE_MUTEX(sysfb_lock);
+static struct platform_device *sysfb_dev;
+
+int __init sysfb_register(const char *name, int id,
+                       const struct resource *res, unsigned int res_num,
+                       const void *data, size_t data_size)
+{
+     struct platform_device *pd;
+     int ret = 0;
+
+     mutex_lock(&sysfb_lock);
+     if (!sysfb_dev) {
+             pd = platform_device_register_resndata(NULL, name, id,
+                                                    res, res_num,
+                                                    data, data_size);
+             if (IS_ERR(pd))
+                     ret = PTR_ERR(pd);
+             else
+                     sysfb_dev = pd;
+     }
+     mutex_unlock(&sysfb_lock);
+
+     return ret;
+}
+
+static bool sysfb_match(const struct apertures_struct *apert)
+{
+     struct screen_info *si = &screen_info;
+     unsigned int i;
+     const struct aperture *a;
+
+     for (i = 0; i < apert->count; ++i) {
+             a = &apert->ranges[i];
+             if (a->base >= si->lfb_base &&
+                 a->base < si->lfb_base + ((u64)si->lfb_size << 16))
+                     return true;
+             if (si->lfb_base >= a->base &&
+                 si->lfb_base < a->base + a->size)
+                     return true;
+     }
+
+     return false;
+}
+
+/* Remove sysfb and disallow new sysfbs from now on. Can be called from any
+ * context except recursively (see also remove_conflicting_framebuffers()). */
+void sysfb_unregister(const struct apertures_struct *apert, bool primary)

Please use the customary (multi-line) comment style:

  /*
   * Comment .....
   * ...... goes here.
   */

specified in Documentation/CodingStyle.

Whoops, will fix it up. Still used to that from HID code.

quoted

+#ifdef CONFIG_X86_SYSFB
+#  include <asm/sysfb.h>
+#endif

I guess a single space is sufficient?

Better yet, I'd include sysfb.h unconditionally:

Unconditionally won't work as only x86 has this header. If there's a
way to place a dummy into asm-generic which is picked if
arch/xy/include/asm/ doesn't have the header, let me know. But if I
include it unconditionally without any fallback, this will fail on
non-x86.
And adding the header to all archs seems overkill.

quoted

@@ -1773,6 +1780,10 @@ register_framebuffer(struct fb_info *fb_info)
 {
      int ret;

+#ifdef CONFIG_X86_SYSFB
+     sysfb_unregister(fb_info->apertures, fb_is_primary_device(fb_info));
+#endif

So, if a dummy sysfb_unregister() inline was defined in the
!CONFIG_X86_SYSFB case then this ugly #ifdef could possibly be
removed? Especially as it's used twice.

Again, this is fine for x86, but not for other archs. I would still
need the #ifdef x86.
Note that patch #6 introduces linux/sysfb.h and removes all these ugly
#ifdefs again. They're only needed to fix the x86 code *now*. Patch #6
generalizes the x86-sysfb infrastructure and makes it
arch-independent. But Patch #6 introduces new features and thus
shouldn't go to stable or 3.14.

As Patch #1 already fixes nearly all issues with sysfb, let me know if
you want to drop this patch and just wait for the arch-independent
sysfb to get merged. This patch is only needed if people enable
X86_SYSFB *and* FB_SIMPLE *purposely* and want hw-handover. The case
were people enable it accidentally is fixed by Patch #1.
The situation is kind of screwed.. sorry for that.

Thanks
David