vga: vgastate fix

1) sets 'palette access disabled' during read from AR10.
   This is usually documented as needed for access AR01-AR0F,
   but on ARK Logic card it is needed for AR10 (otherwise read
   returns some nonsence and save_vga_text() returns before do
   anything).

2) do not restore AR10, because it was not changed during

3) remove modification of misc reg:
        /* force graphics mode */
        vga_w(state->vgabase, VGA_MIS_W, misc | 1);

   as comment is misleading - LSB of misc reg does not set/reset graphics
   mode, but set color/mono adresses of CRT and some other regs.
   but these regs are not used during save/restore fonts.
   (it worked even when (misc | 1) was replaced by (misc & ~1) ).

Signed-off-by: Ondrej Zajicek <santiago@crfreenet.org>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 15 deletions

diff --git a/drivers/video/vgastate.c b/drivers/video/vgastate.c
index d94efafc77b5..b91c466225b9 100644
--- a/drivers/video/vgastate.c
+++ b/drivers/video/vgastate.c
@@ -50,23 +50,28 @@ static void save_vga_text(struct vgastate *state, void __iomem *fbbase)
         struct regstate *saved = (struct regstate *) state->vidstate;
         int i;
         u8 misc, attr10, gr4, gr5, gr6, seq1, seq2, seq4;
+        unsigned short iobase;
 
         /* if in graphics mode, no need to save */
+        misc = vga_r(state->vgabase, VGA_MIS_R);
+        iobase = (misc & 1) ? 0x3d0 : 0x3b0;
+
+        vga_r(state->vgabase, iobase + 0xa);
+        vga_w(state->vgabase, VGA_ATT_W, 0x00);
         attr10 = vga_rattr(state->vgabase, 0x10);
+        vga_r(state->vgabase, iobase + 0xa);
+        vga_w(state->vgabase, VGA_ATT_W, 0x20);
+
         if (attr10 & 1)
                 return;
-        
+
         /* save regs */
-        misc = vga_r(state->vgabase, VGA_MIS_R);
         gr4 = vga_rgfx(state->vgabase, VGA_GFX_PLANE_READ);
         gr5 = vga_rgfx(state->vgabase, VGA_GFX_MODE);
         gr6 = vga_rgfx(state->vgabase, VGA_GFX_MISC);
         seq2 = vga_rseq(state->vgabase, VGA_SEQ_PLANE_WRITE);
         seq4 = vga_rseq(state->vgabase, VGA_SEQ_MEMORY_MODE);
         
-        /* force graphics mode */
-        vga_w(state->vgabase, VGA_MIS_W, misc | 1);
-
         /* blank screen */
         seq1 = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
@@ -115,15 +120,12 @@ static void save_vga_text(struct vgastate *state, void __iomem *fbbase)
         }
 
         /* restore regs */
-        vga_wattr(state->vgabase, 0x10, attr10);
-
         vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, seq2);
         vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, seq4);
 
         vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, gr4);
         vga_wgfx(state->vgabase, VGA_GFX_MODE, gr5);
         vga_wgfx(state->vgabase, VGA_GFX_MISC, gr6);
-        vga_w(state->vgabase, VGA_MIS_W, misc);
 
         /* unblank screen */
         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
@@ -137,11 +139,10 @@ static void restore_vga_text(struct vgastate *state, void __iomem *fbbase)
 {
         struct regstate *saved = (struct regstate *) state->vidstate;
         int i;
-        u8 misc, gr1, gr3, gr4, gr5, gr6, gr8; 
+        u8 gr1, gr3, gr4, gr5, gr6, gr8;
         u8 seq1, seq2, seq4;
 
         /* save regs */
-        misc = vga_r(state->vgabase, VGA_MIS_R);
         gr1 = vga_rgfx(state->vgabase, VGA_GFX_SR_ENABLE);
         gr3 = vga_rgfx(state->vgabase, VGA_GFX_DATA_ROTATE);
         gr4 = vga_rgfx(state->vgabase, VGA_GFX_PLANE_READ);
@@ -151,9 +152,6 @@ static void restore_vga_text(struct vgastate *state, void __iomem *fbbase)
         seq2 = vga_rseq(state->vgabase, VGA_SEQ_PLANE_WRITE);
         seq4 = vga_rseq(state->vgabase, VGA_SEQ_MEMORY_MODE);
         
-        /* force graphics mode */
-        vga_w(state->vgabase, VGA_MIS_W, misc | 1);
-
         /* blank screen */
         seq1 = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
@@ -213,8 +211,6 @@ static void restore_vga_text(struct vgastate *state, void __iomem *fbbase)
         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
 
         /* restore regs */
-        vga_w(state->vgabase, VGA_MIS_W, misc);
-
         vga_wgfx(state->vgabase, VGA_GFX_SR_ENABLE, gr1);
         vga_wgfx(state->vgabase, VGA_GFX_DATA_ROTATE, gr3);
         vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, gr4);