Move the calculation of the bits per pixels for screen_info into a
helper function. This will make it available to other callers besides
the firmware code.
Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
---
drivers/firmware/sysfb_simplefb.c | 31 +------------------------
drivers/video/screen_info_generic.c | 36 +++++++++++++++++++++++++++++
include/linux/screen_info.h | 2 ++
3 files changed, 39 insertions(+), 30 deletions(-)
diff --git a/drivers/firmware/sysfb_simplefb.c
b/drivers/firmware/sysfb_simplefb.c
index 75a186bf8f8e..592d8a644619 100644
--- a/drivers/firmware/sysfb_simplefb.c
+++ b/drivers/firmware/sysfb_simplefb.c
@@ -35,36 +35,7 @@ __init bool sysfb_parse_mode(const struct screen_info *si,
if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI)
return false;
- /*
- * The meaning of depth and bpp for direct-color formats is
- * inconsistent:
- *
- * - DRM format info specifies depth as the number of color
- * bits; including alpha, but not including filler bits.
- * - Linux' EFI platform code computes lfb_depth from the
- * individual color channels, including the reserved bits.
- * - VBE 1.1 defines lfb_depth for XRGB1555 as 16, but later
- * versions use 15.
- * - On the kernel command line, 'bpp' of 32 is usually
- * XRGB8888 including the filler bits, but 15 is XRGB1555
- * not including the filler bit.
- *
- * It's not easily possible to fix this in struct screen_info,
- * as this could break UAPI. The best solution is to compute
- * bits_per_pixel from the color bits, reserved bits and
- * reported lfb_depth, whichever is highest. In the loop below,
- * ignore simplefb formats with alpha bits, as EFI and VESA
- * don't specify alpha channels.
- */
- if (si->lfb_depth > 8) {
- bits_per_pixel = max(max3(si->red_size + si->red_pos,
- si->green_size + si->green_pos,
- si->blue_size + si->blue_pos),
- si->rsvd_size + si->rsvd_pos);
- bits_per_pixel = max_t(u32, bits_per_pixel, si->lfb_depth);
- } else {
- bits_per_pixel = si->lfb_depth;
- }
+ bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);
for (i = 0; i < ARRAY_SIZE(formats); ++i) {
const struct simplefb_format *f = &formats[i];
diff --git a/drivers/video/screen_info_generic.c
b/drivers/video/screen_info_generic.c
index 64117c6367ab..900e9386eceb 100644
--- a/drivers/video/screen_info_generic.c
+++ b/drivers/video/screen_info_generic.c
@@ -144,3 +144,39 @@ ssize_t screen_info_resources(const struct screen_info
*si, struct resource *r,
return pos - r;
}
EXPORT_SYMBOL(screen_info_resources);
+
+/*
+ * The meaning of depth and bpp for direct-color formats is
+ * inconsistent:
+ *
+ * - DRM format info specifies depth as the number of color
+ * bits; including alpha, but not including filler bits.
+ * - Linux' EFI platform code computes lfb_depth from the
+ * individual color channels, including the reserved bits.
+ * - VBE 1.1 defines lfb_depth for XRGB1555 as 16, but later
+ * versions use 15.
+ * - On the kernel command line, 'bpp' of 32 is usually
+ * XRGB8888 including the filler bits, but 15 is XRGB1555
+ * not including the filler bit.
+ *
+ * It is not easily possible to fix this in struct screen_info,
+ * as this could break UAPI. The best solution is to compute
+ * bits_per_pixel from the color bits, reserved bits and
+ * reported lfb_depth, whichever is highest.
+ */
+
+u32 __screen_info_lfb_bits_per_pixel(const struct screen_info *si)
+{
+ u32 bits_per_pixel = si->lfb_depth;
+
+ if (bits_per_pixel > 8) {
+ bits_per_pixel = max(max3(si->red_size + si->red_pos,
+ si->green_size + si->green_pos,
+ si->blue_size + si->blue_pos),
+ si->rsvd_size + si->rsvd_pos);
+ bits_per_pixel = max_t(u32, bits_per_pixel, si->lfb_depth);
+ }
+
+ return bits_per_pixel;
+}
+EXPORT_SYMBOL(__screen_info_lfb_bits_per_pixel);
diff --git a/include/linux/screen_info.h b/include/linux/screen_info.h
index 6a4a3cec4638..ab3cffbb58b7 100644
--- a/include/linux/screen_info.h
+++ b/include/linux/screen_info.h
@@ -128,6 +128,8 @@ static inline unsigned int screen_info_video_type(const
struct screen_info *si)
ssize_t screen_info_resources(const struct screen_info *si, struct resource
*r, size_t num);
+u32 __screen_info_lfb_bits_per_pixel(const struct screen_info *si);
+
#if defined(CONFIG_PCI)
void screen_info_apply_fixups(void);
struct pci_dev *screen_info_pci_dev(const struct screen_info *si);
--
2.48.1
