--- /dev/null
+From a3f781a9d6114c1d1e01defb7aa234dec45d2a5f Mon Sep 17 00:00:00 2001
+From: Helge Deller <deller@gmx.de>
+Date: Wed, 2 Feb 2022 14:55:31 +0100
+Subject: fbcon: Add option to enable legacy hardware acceleration
+
+From: Helge Deller <deller@gmx.de>
+
+commit a3f781a9d6114c1d1e01defb7aa234dec45d2a5f upstream.
+
+Add a config option CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION to
+enable bitblt and fillrect hardware acceleration in the framebuffer
+console. If disabled, such acceleration will not be used, even if it is
+supported by the graphics hardware driver.
+
+If you plan to use DRM as your main graphics output system, you should
+disable this option since it will prevent compiling in code which isn't
+used later on when DRM takes over.
+
+For all other configurations, e.g. if none of your graphic cards support
+DRM (yet), DRM isn't available for your architecture, or you can't be
+sure that the graphic card in the target system will support DRM, you
+most likely want to enable this option.
+
+In the non-accelerated case (e.g. when DRM is used), the inlined
+fb_scrollmode() function is hardcoded to return SCROLL_REDRAW and as such the
+compiler is able to optimize much unneccesary code away.
+
+In this v3 patch version I additionally changed the GETVYRES() and GETVXRES()
+macros to take a pointer to the fbcon_display struct. This fixes the build when
+console rotation is enabled and helps the compiler again to optimize out code.
+
+Signed-off-by: Helge Deller <deller@gmx.de>
+Cc: stable@vger.kernel.org # v5.10+
+Signed-off-by: Helge Deller <deller@gmx.de>
+Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
+Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-4-deller@gmx.de
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/video/console/Kconfig | 20 ++++++++++++++++
+ drivers/video/fbdev/core/fbcon.c | 39 ++++++++++++++++++++++----------
+ drivers/video/fbdev/core/fbcon.h | 15 +++++++++++-
+ drivers/video/fbdev/core/fbcon_ccw.c | 10 ++++----
+ drivers/video/fbdev/core/fbcon_cw.c | 10 ++++----
+ drivers/video/fbdev/core/fbcon_rotate.h | 4 +--
+ drivers/video/fbdev/core/fbcon_ud.c | 20 ++++++++--------
+ 7 files changed, 84 insertions(+), 34 deletions(-)
+
+--- a/drivers/video/console/Kconfig
++++ b/drivers/video/console/Kconfig
+@@ -78,6 +78,26 @@ config FRAMEBUFFER_CONSOLE
+ help
+ Low-level framebuffer-based console driver.
+
++config FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
++ bool "Enable legacy fbcon hardware acceleration code"
++ depends on FRAMEBUFFER_CONSOLE
++ default y if PARISC
++ default n
++ help
++ This option enables the fbcon (framebuffer text-based) hardware
++ acceleration for graphics drivers which were written for the fbdev
++ graphics interface.
++
++ On modern machines, on mainstream machines (like x86-64) or when
++ using a modern Linux distribution those fbdev drivers usually aren't used.
++ So enabling this option wouldn't have any effect, which is why you want
++ to disable this option on such newer machines.
++
++ If you compile this kernel for older machines which still require the
++ fbdev drivers, you may want to say Y.
++
++ If unsure, select n.
++
+ config FRAMEBUFFER_CONSOLE_DETECT_PRIMARY
+ bool "Map the console to the primary display device"
+ depends on FRAMEBUFFER_CONSOLE
+--- a/drivers/video/fbdev/core/fbcon.c
++++ b/drivers/video/fbdev/core/fbcon.c
+@@ -1147,11 +1147,13 @@ static void fbcon_init(struct vc_data *v
+
+ ops->graphics = 0;
+
++#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
+ if ((cap & FBINFO_HWACCEL_COPYAREA) &&
+ !(cap & FBINFO_HWACCEL_DISABLED))
+ p->scrollmode = SCROLL_MOVE;
+ else /* default to something safe */
+ p->scrollmode = SCROLL_REDRAW;
++#endif
+
+ /*
+ * ++guenther: console.c:vc_allocate() relies on initializing
+@@ -1717,7 +1719,7 @@ static bool fbcon_scroll(struct vc_data
+ count = vc->vc_rows;
+ if (logo_shown >= 0)
+ goto redraw_up;
+- switch (p->scrollmode) {
++ switch (fb_scrollmode(p)) {
+ case SCROLL_MOVE:
+ fbcon_redraw_blit(vc, info, p, t, b - t - count,
+ count);
+@@ -1807,7 +1809,7 @@ static bool fbcon_scroll(struct vc_data
+ count = vc->vc_rows;
+ if (logo_shown >= 0)
+ goto redraw_down;
+- switch (p->scrollmode) {
++ switch (fb_scrollmode(p)) {
+ case SCROLL_MOVE:
+ fbcon_redraw_blit(vc, info, p, b - 1, b - t - count,
+ -count);
+@@ -1958,12 +1960,12 @@ static void fbcon_bmove_rec(struct vc_da
+ height, width);
+ }
+
+-static void updatescrollmode(struct fbcon_display *p,
++static void updatescrollmode_accel(struct fbcon_display *p,
+ struct fb_info *info,
+ struct vc_data *vc)
+ {
++#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
+ struct fbcon_ops *ops = info->fbcon_par;
+- int fh = vc->vc_font.height;
+ int cap = info->flags;
+ u16 t = 0;
+ int ypan = FBCON_SWAP(ops->rotate, info->fix.ypanstep,
+@@ -1984,12 +1986,6 @@ static void updatescrollmode(struct fbco
+ int fast_imageblit = (cap & FBINFO_HWACCEL_IMAGEBLIT) &&
+ !(cap & FBINFO_HWACCEL_DISABLED);
+
+- p->vrows = vyres/fh;
+- if (yres > (fh * (vc->vc_rows + 1)))
+- p->vrows -= (yres - (fh * vc->vc_rows)) / fh;
+- if ((yres % fh) && (vyres % fh < yres % fh))
+- p->vrows--;
+-
+ if (good_wrap || good_pan) {
+ if (reading_fast || fast_copyarea)
+ p->scrollmode = good_wrap ?
+@@ -2003,6 +1999,27 @@ static void updatescrollmode(struct fbco
+ else
+ p->scrollmode = SCROLL_REDRAW;
+ }
++#endif
++}
++
++static void updatescrollmode(struct fbcon_display *p,
++ struct fb_info *info,
++ struct vc_data *vc)
++{
++ struct fbcon_ops *ops = info->fbcon_par;
++ int fh = vc->vc_font.height;
++ int yres = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
++ int vyres = FBCON_SWAP(ops->rotate, info->var.yres_virtual,
++ info->var.xres_virtual);
++
++ p->vrows = vyres/fh;
++ if (yres > (fh * (vc->vc_rows + 1)))
++ p->vrows -= (yres - (fh * vc->vc_rows)) / fh;
++ if ((yres % fh) && (vyres % fh < yres % fh))
++ p->vrows--;
++
++ /* update scrollmode in case hardware acceleration is used */
++ updatescrollmode_accel(p, info, vc);
+ }
+
+ #define PITCH(w) (((w) + 7) >> 3)
+@@ -2163,7 +2180,7 @@ static int fbcon_switch(struct vc_data *
+
+ updatescrollmode(p, info, vc);
+
+- switch (p->scrollmode) {
++ switch (fb_scrollmode(p)) {
+ case SCROLL_WRAP_MOVE:
+ scrollback_phys_max = p->vrows - vc->vc_rows;
+ break;
+--- a/drivers/video/fbdev/core/fbcon.h
++++ b/drivers/video/fbdev/core/fbcon.h
+@@ -29,7 +29,9 @@ struct fbcon_display {
+ /* Filled in by the low-level console driver */
+ const u_char *fontdata;
+ int userfont; /* != 0 if fontdata kmalloc()ed */
+- u_short scrollmode; /* Scroll Method */
++#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
++ u_short scrollmode; /* Scroll Method, use fb_scrollmode() */
++#endif
+ u_short inverse; /* != 0 text black on white as default */
+ short yscroll; /* Hardware scrolling */
+ int vrows; /* number of virtual rows */
+@@ -208,6 +210,17 @@ static inline int attr_col_ec(int shift,
+ #define SCROLL_REDRAW 0x004
+ #define SCROLL_PAN_REDRAW 0x005
+
++static inline u_short fb_scrollmode(struct fbcon_display *fb)
++{
++#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
++ return fb->scrollmode;
++#else
++ /* hardcoded to SCROLL_REDRAW if acceleration was disabled. */
++ return SCROLL_REDRAW;
++#endif
++}
++
++
+ #ifdef CONFIG_FB_TILEBLITTING
+ extern void fbcon_set_tileops(struct vc_data *vc, struct fb_info *info);
+ #endif
+--- a/drivers/video/fbdev/core/fbcon_ccw.c
++++ b/drivers/video/fbdev/core/fbcon_ccw.c
+@@ -65,7 +65,7 @@ static void ccw_bmove(struct vc_data *vc
+ {
+ struct fbcon_ops *ops = info->fbcon_par;
+ struct fb_copyarea area;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
+
+ area.sx = sy * vc->vc_font.height;
+ area.sy = vyres - ((sx + width) * vc->vc_font.width);
+@@ -83,7 +83,7 @@ static void ccw_clear(struct vc_data *vc
+ struct fbcon_ops *ops = info->fbcon_par;
+ struct fb_fillrect region;
+ int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
+
+ region.color = attr_bgcol_ec(bgshift,vc,info);
+ region.dx = sy * vc->vc_font.height;
+@@ -140,7 +140,7 @@ static void ccw_putcs(struct vc_data *vc
+ u32 cnt, pitch, size;
+ u32 attribute = get_attribute(info, scr_readw(s));
+ u8 *dst, *buf = NULL;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
+
+ if (!ops->fontbuffer)
+ return;
+@@ -229,7 +229,7 @@ static void ccw_cursor(struct vc_data *v
+ int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
+ int err = 1, dx, dy;
+ char *src;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
+
+ if (!ops->fontbuffer)
+ return;
+@@ -387,7 +387,7 @@ static int ccw_update_start(struct fb_in
+ {
+ struct fbcon_ops *ops = info->fbcon_par;
+ u32 yoffset;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
+ int err;
+
+ yoffset = (vyres - info->var.yres) - ops->var.xoffset;
+--- a/drivers/video/fbdev/core/fbcon_cw.c
++++ b/drivers/video/fbdev/core/fbcon_cw.c
+@@ -50,7 +50,7 @@ static void cw_bmove(struct vc_data *vc,
+ {
+ struct fbcon_ops *ops = info->fbcon_par;
+ struct fb_copyarea area;
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ area.sx = vxres - ((sy + height) * vc->vc_font.height);
+ area.sy = sx * vc->vc_font.width;
+@@ -68,7 +68,7 @@ static void cw_clear(struct vc_data *vc,
+ struct fbcon_ops *ops = info->fbcon_par;
+ struct fb_fillrect region;
+ int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ region.color = attr_bgcol_ec(bgshift,vc,info);
+ region.dx = vxres - ((sy + height) * vc->vc_font.height);
+@@ -125,7 +125,7 @@ static void cw_putcs(struct vc_data *vc,
+ u32 cnt, pitch, size;
+ u32 attribute = get_attribute(info, scr_readw(s));
+ u8 *dst, *buf = NULL;
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ if (!ops->fontbuffer)
+ return;
+@@ -212,7 +212,7 @@ static void cw_cursor(struct vc_data *vc
+ int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
+ int err = 1, dx, dy;
+ char *src;
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ if (!ops->fontbuffer)
+ return;
+@@ -369,7 +369,7 @@ static void cw_cursor(struct vc_data *vc
+ static int cw_update_start(struct fb_info *info)
+ {
+ struct fbcon_ops *ops = info->fbcon_par;
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vxres = GETVXRES(ops->p, info);
+ u32 xoffset;
+ int err;
+
+--- a/drivers/video/fbdev/core/fbcon_rotate.h
++++ b/drivers/video/fbdev/core/fbcon_rotate.h
+@@ -12,11 +12,11 @@
+ #define _FBCON_ROTATE_H
+
+ #define GETVYRES(s,i) ({ \
+- (s == SCROLL_REDRAW || s == SCROLL_MOVE) ? \
++ (fb_scrollmode(s) == SCROLL_REDRAW || fb_scrollmode(s) == SCROLL_MOVE) ? \
+ (i)->var.yres : (i)->var.yres_virtual; })
+
+ #define GETVXRES(s,i) ({ \
+- (s == SCROLL_REDRAW || s == SCROLL_MOVE || !(i)->fix.xpanstep) ? \
++ (fb_scrollmode(s) == SCROLL_REDRAW || fb_scrollmode(s) == SCROLL_MOVE || !(i)->fix.xpanstep) ? \
+ (i)->var.xres : (i)->var.xres_virtual; })
+
+
+--- a/drivers/video/fbdev/core/fbcon_ud.c
++++ b/drivers/video/fbdev/core/fbcon_ud.c
+@@ -50,8 +50,8 @@ static void ud_bmove(struct vc_data *vc,
+ {
+ struct fbcon_ops *ops = info->fbcon_par;
+ struct fb_copyarea area;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ area.sy = vyres - ((sy + height) * vc->vc_font.height);
+ area.sx = vxres - ((sx + width) * vc->vc_font.width);
+@@ -69,8 +69,8 @@ static void ud_clear(struct vc_data *vc,
+ struct fbcon_ops *ops = info->fbcon_par;
+ struct fb_fillrect region;
+ int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ region.color = attr_bgcol_ec(bgshift,vc,info);
+ region.dy = vyres - ((sy + height) * vc->vc_font.height);
+@@ -162,8 +162,8 @@ static void ud_putcs(struct vc_data *vc,
+ u32 mod = vc->vc_font.width % 8, cnt, pitch, size;
+ u32 attribute = get_attribute(info, scr_readw(s));
+ u8 *dst, *buf = NULL;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ if (!ops->fontbuffer)
+ return;
+@@ -259,8 +259,8 @@ static void ud_cursor(struct vc_data *vc
+ int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
+ int err = 1, dx, dy;
+ char *src;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
++ u32 vxres = GETVXRES(ops->p, info);
+
+ if (!ops->fontbuffer)
+ return;
+@@ -410,8 +410,8 @@ static int ud_update_start(struct fb_inf
+ {
+ struct fbcon_ops *ops = info->fbcon_par;
+ int xoffset, yoffset;
+- u32 vyres = GETVYRES(ops->p->scrollmode, info);
+- u32 vxres = GETVXRES(ops->p->scrollmode, info);
++ u32 vyres = GETVYRES(ops->p, info);
++ u32 vxres = GETVXRES(ops->p, info);
+ int err;
+
+ xoffset = vxres - info->var.xres - ops->var.xoffset;
--- /dev/null
+From 87ab9f6b7417349aa197a6c7098d4fdd4beebb74 Mon Sep 17 00:00:00 2001
+From: Helge Deller <deller@gmx.de>
+Date: Wed, 2 Feb 2022 14:55:30 +0100
+Subject: Revert "fbcon: Disable accelerated scrolling"
+
+From: Helge Deller <deller@gmx.de>
+
+commit 87ab9f6b7417349aa197a6c7098d4fdd4beebb74 upstream.
+
+This reverts commit 39aead8373b3c20bb5965c024dfb51a94e526151.
+
+Revert the first (of 2) commits which disabled scrolling acceleration in
+fbcon/fbdev. It introduced a regression for fbdev-supported graphic cards
+because of the performance penalty by doing screen scrolling by software
+instead of using the existing graphic card 2D hardware acceleration.
+
+Console scrolling acceleration was disabled by dropping code which
+checked at runtime the driver hardware capabilities for the
+BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
+enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
+screen contents. After dropping those checks scrollmode was hard-wired
+to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
+character at the new screen position when scrolling.
+
+This change effectively disabled all hardware-based scrolling acceleration for
+ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
+fillrect) in the drivers isn't used any longer.
+
+The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
+and gma500) used hardware acceleration in the past and thus code for checking
+and using scrolling acceleration is obsolete.
+
+This statement is NOT TRUE, because beside the DRM drivers there are around 35
+other fbdev drivers which depend on fbdev/fbcon and still provide hardware
+acceleration for fbdev/fbcon.
+
+The original commit message also states that syzbot found lots of bugs in fbcon
+and thus it's "often the solution to just delete code and remove features".
+This is true, and the bugs - which actually affected all users of fbcon,
+including DRM - were fixed, or code was dropped like e.g. the support for
+software scrollback in vgacon (commit 973c096f6a85).
+
+So to further analyze which bugs were found by syzbot, I've looked through all
+patches in drivers/video which were tagged with syzbot or syzkaller back to
+year 2005. The vast majority fixed the reported issues on a higher level, e.g.
+when screen is to be resized, or when font size is to be changed. The few ones
+which touched driver code fixed a real driver bug, e.g. by adding a check.
+
+But NONE of those patches touched code of either the SCROLL_MOVE or the
+SCROLL_REDRAW case.
+
+That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
+just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
+was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
+could go away. That argument completely missed the fact that SCROLL_MOVE is
+still heavily used by fbdev (non-DRM) drivers.
+
+Some people mention that using memcpy() instead of the hardware acceleration is
+pretty much the same speed. But that's not true, at least not for older graphic
+cards and machines where we see speed decreases by factor 10 and more and thus
+this change leads to console responsiveness way worse than before.
+
+That's why the original commit is to be reverted. By reverting we
+reintroduce hardware-based scrolling acceleration and fix the
+performance regression for fbdev drivers.
+
+There isn't any impact on DRM when reverting those patches.
+
+Signed-off-by: Helge Deller <deller@gmx.de>
+Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
+Acked-by: Sven Schnelle <svens@stackframe.org>
+Cc: stable@vger.kernel.org # v5.10+
+Signed-off-by: Helge Deller <deller@gmx.de>
+Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
+Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-3-deller@gmx.de
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/gpu/todo.rst | 18 ---------------
+ drivers/video/fbdev/core/fbcon.c | 45 ++++++++++++++++++++++++++++++++-------
+ 2 files changed, 37 insertions(+), 26 deletions(-)
+
+--- a/Documentation/gpu/todo.rst
++++ b/Documentation/gpu/todo.rst
+@@ -273,24 +273,6 @@ Contact: Daniel Vetter, Noralf Tronnes
+
+ Level: Advanced
+
+-Garbage collect fbdev scrolling acceleration
+---------------------------------------------
+-
+-Scroll acceleration is disabled in fbcon by hard-wiring p->scrollmode =
+-SCROLL_REDRAW. There's a ton of code this will allow us to remove:
+-- lots of code in fbcon.c
+-- a bunch of the hooks in fbcon_ops, maybe the remaining hooks could be called
+- directly instead of the function table (with a switch on p->rotate)
+-- fb_copyarea is unused after this, and can be deleted from all drivers
+-
+-Note that not all acceleration code can be deleted, since clearing and cursor
+-support is still accelerated, which might be good candidates for further
+-deletion projects.
+-
+-Contact: Daniel Vetter
+-
+-Level: Intermediate
+-
+ idr_init_base()
+ ---------------
+
+--- a/drivers/video/fbdev/core/fbcon.c
++++ b/drivers/video/fbdev/core/fbcon.c
+@@ -1033,7 +1033,7 @@ static void fbcon_init(struct vc_data *v
+ struct vc_data *svc = *default_mode;
+ struct fbcon_display *t, *p = &fb_display[vc->vc_num];
+ int logo = 1, new_rows, new_cols, rows, cols, charcnt = 256;
+- int ret;
++ int cap, ret;
+
+ if (WARN_ON(info_idx == -1))
+ return;
+@@ -1042,6 +1042,7 @@ static void fbcon_init(struct vc_data *v
+ con2fb_map[vc->vc_num] = info_idx;
+
+ info = registered_fb[con2fb_map[vc->vc_num]];
++ cap = info->flags;
+
+ if (logo_shown < 0 && console_loglevel <= CONSOLE_LOGLEVEL_QUIET)
+ logo_shown = FBCON_LOGO_DONTSHOW;
+@@ -1146,13 +1147,11 @@ static void fbcon_init(struct vc_data *v
+
+ ops->graphics = 0;
+
+- /*
+- * No more hw acceleration for fbcon.
+- *
+- * FIXME: Garbage collect all the now dead code after sufficient time
+- * has passed.
+- */
+- p->scrollmode = SCROLL_REDRAW;
++ if ((cap & FBINFO_HWACCEL_COPYAREA) &&
++ !(cap & FBINFO_HWACCEL_DISABLED))
++ p->scrollmode = SCROLL_MOVE;
++ else /* default to something safe */
++ p->scrollmode = SCROLL_REDRAW;
+
+ /*
+ * ++guenther: console.c:vc_allocate() relies on initializing
+@@ -1965,15 +1964,45 @@ static void updatescrollmode(struct fbco
+ {
+ struct fbcon_ops *ops = info->fbcon_par;
+ int fh = vc->vc_font.height;
++ int cap = info->flags;
++ u16 t = 0;
++ int ypan = FBCON_SWAP(ops->rotate, info->fix.ypanstep,
++ info->fix.xpanstep);
++ int ywrap = FBCON_SWAP(ops->rotate, info->fix.ywrapstep, t);
+ int yres = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
+ int vyres = FBCON_SWAP(ops->rotate, info->var.yres_virtual,
+ info->var.xres_virtual);
++ int good_pan = (cap & FBINFO_HWACCEL_YPAN) &&
++ divides(ypan, vc->vc_font.height) && vyres > yres;
++ int good_wrap = (cap & FBINFO_HWACCEL_YWRAP) &&
++ divides(ywrap, vc->vc_font.height) &&
++ divides(vc->vc_font.height, vyres) &&
++ divides(vc->vc_font.height, yres);
++ int reading_fast = cap & FBINFO_READS_FAST;
++ int fast_copyarea = (cap & FBINFO_HWACCEL_COPYAREA) &&
++ !(cap & FBINFO_HWACCEL_DISABLED);
++ int fast_imageblit = (cap & FBINFO_HWACCEL_IMAGEBLIT) &&
++ !(cap & FBINFO_HWACCEL_DISABLED);
+
+ p->vrows = vyres/fh;
+ if (yres > (fh * (vc->vc_rows + 1)))
+ p->vrows -= (yres - (fh * vc->vc_rows)) / fh;
+ if ((yres % fh) && (vyres % fh < yres % fh))
+ p->vrows--;
++
++ if (good_wrap || good_pan) {
++ if (reading_fast || fast_copyarea)
++ p->scrollmode = good_wrap ?
++ SCROLL_WRAP_MOVE : SCROLL_PAN_MOVE;
++ else
++ p->scrollmode = good_wrap ? SCROLL_REDRAW :
++ SCROLL_PAN_REDRAW;
++ } else {
++ if (reading_fast || (fast_copyarea && !fast_imageblit))
++ p->scrollmode = SCROLL_MOVE;
++ else
++ p->scrollmode = SCROLL_REDRAW;
++ }
+ }
+
+ #define PITCH(w) (((w) + 7) >> 3)
projects / thirdparty / kernel / stable-queue.git / commitdiff
