Add support for panning at vertical blanking to the matroxfb. Now mplayer output

looks much better on primary output (secondary output is always synced with vbl).

drivers/video/matrox/matroxfb_DAC1064.c

@@ -1036,6 +1036,7 @@ static void MGA1064_restore(WPMINFO2) {
 
 	DAC1064_restore_1(PMINFO2);
 	matroxfb_vgaHWrestore(PMINFO2);
+	ACCESS_FBINFO(crtc1.panpos) = -1;
 	for (i = 0; i < 6; i++)
 		mga_setr(M_EXTVGA_INDEX, i, hw->CRTCEXT[i]);
 	DAC1064_restore_2(PMINFO2);
@@ -1062,6 +1063,7 @@ static void MGAG100_restore(WPMINFO2) {
 	if (ACCESS_FBINFO(devflags.support32MB))
 		mga_setr(M_EXTVGA_INDEX, 8, hw->CRTCEXT[8]);
 #endif
+	ACCESS_FBINFO(crtc1.panpos) = -1;
 	for (i = 0; i < 6; i++)
 		mga_setr(M_EXTVGA_INDEX, i, hw->CRTCEXT[i]);
 	DAC1064_restore_2(PMINFO2);

drivers/video/matrox/matroxfb_Ti3026.c

@@ -575,6 +575,7 @@ static void Ti3026_restore(WPMINFO2) {
 
 	CRITBEGIN
 
+	ACCESS_FBINFO(crtc1.panpos) = -1;
 	for (i = 0; i < 6; i++)
 		mga_setr(M_EXTVGA_INDEX, i, hw->CRTCEXT[i]);
 

drivers/video/matrox/matroxfb_base.c

@@ -176,6 +176,27 @@ static void update_crtc2(WPMINFO unsigned int pos) {
 	}
 }
 
+static void matroxfb_crtc1_panpos(WPMINFO2) {
+	if (ACCESS_FBINFO(crtc1.panpos) >= 0) {
+		unsigned long flags;
+		int panpos;
+
+		matroxfb_DAC_lock_irqsave(flags);
+		panpos = ACCESS_FBINFO(crtc1.panpos);
+		if (panpos >= 0) {
+			unsigned int extvga_reg;
+
+			ACCESS_FBINFO(crtc1.panpos) = -1; /* No update pending anymore */
+			extvga_reg = mga_inb(M_EXTVGA_INDEX);
+			mga_setr(M_EXTVGA_INDEX, 0x00, panpos);
+			if (extvga_reg != 0x00) {
+				mga_outb(M_EXTVGA_INDEX, extvga_reg);
+			}
+		}
+		matroxfb_DAC_unlock_irqrestore(flags);
+	}
+}
+
 static irqreturn_t matrox_irq(int irq, void *dev_id, struct pt_regs *fp)
 {
 	u_int32_t status;
@@ -188,6 +209,7 @@ static irqreturn_t matrox_irq(int irq, void *dev_id, struct pt_regs *fp)
 	if (status & 0x20) {
 		mga_outl(M_ICLEAR, 0x20);
 		ACCESS_FBINFO(crtc1.vsync.cnt)++;
+		matroxfb_crtc1_panpos(PMINFO2);
 		wake_up_interruptible(&ACCESS_FBINFO(crtc1.vsync.wait));
 		handled = 1;
 	}
@@ -209,12 +231,13 @@ int matroxfb_enable_irq(WPMINFO int reenable) {
 		bm = 0x020;
 
 	if (!test_and_set_bit(0, &ACCESS_FBINFO(irq_flags))) {
-		printk(KERN_DEBUG "matroxfb: enabling IRQ\n");
 		if (request_irq(ACCESS_FBINFO(pcidev)->irq, matrox_irq,
-				SA_SHIRQ, "MGA Vertical Sync", MINFO)) {
+				SA_SHIRQ, "matroxfb", MINFO)) {
 			clear_bit(0, &ACCESS_FBINFO(irq_flags));
 			return -EINVAL;
 		}
+		/* Clear any pending field interrupts */
+		mga_outl(M_ICLEAR, bm);
 		mga_outl(M_IEN, mga_inl(M_IEN) | bm);
 	} else if (reenable) {
 		u_int32_t ien;
@@ -230,7 +253,8 @@ int matroxfb_enable_irq(WPMINFO int reenable) {
 
 static void matroxfb_disable_irq(WPMINFO2) {
 	if (test_and_clear_bit(0, &ACCESS_FBINFO(irq_flags))) {
-		printk(KERN_DEBUG "matroxfb: disabling IRQ\n");
+		/* Flush pending pan-at-vbl request... */
+		matroxfb_crtc1_panpos(PMINFO2);
 		if (ACCESS_FBINFO(devflags.accelerator) == FB_ACCEL_MATROX_MGAG400)
 			mga_outl(M_IEN, mga_inl(M_IEN) & ~0x220);
 		else
@@ -284,6 +308,9 @@ static void matrox_pan_var(WPMINFO struct fb_var_screeninfo *var) {
 #ifdef CONFIG_FB_MATROX_32MB
 	unsigned int p3;
 #endif
+	int vbl;
+	unsigned long flags;
+
 	CRITFLAGS
 
 	DBG(__FUNCTION__)
@@ -302,15 +329,26 @@ static void matrox_pan_var(WPMINFO struct fb_var_screeninfo *var) {
 	p3 = ACCESS_FBINFO(hw).CRTCEXT[8] = pos >> 21;
 #endif
 
+	/* FB_ACTIVATE_VBL and we can acquire interrupts? Honor FB_ACTIVATE_VBL then... */
+	vbl = (var->activate & FB_ACTIVATE_VBL) && (matroxfb_enable_irq(PMINFO 0) == 0);
+
 	CRITBEGIN
 
+	matroxfb_DAC_lock_irqsave(flags);
 	mga_setr(M_CRTC_INDEX, 0x0D, p0);
 	mga_setr(M_CRTC_INDEX, 0x0C, p1);
 #ifdef CONFIG_FB_MATROX_32MB
 	if (ACCESS_FBINFO(devflags.support32MB))
 		mga_setr(M_EXTVGA_INDEX, 0x08, p3);
 #endif
-	mga_setr(M_EXTVGA_INDEX, 0x00, p2);
+	if (vbl) {
+		ACCESS_FBINFO(crtc1.panpos) = p2;
+	} else {
+		/* Abort any pending change */
+		ACCESS_FBINFO(crtc1.panpos) = -1;
+		mga_setr(M_EXTVGA_INDEX, 0x00, p2);
+	}
+	matroxfb_DAC_unlock_irqrestore(flags);
 	
 	update_crtc2(PMINFO pos);
 
@@ -1973,6 +2011,7 @@ static int matroxfb_probe(struct pci_dev* pdev, const struct pci_device_id* dumm
 	ACCESS_FBINFO(irq_flags) = 0;
 	init_waitqueue_head(&ACCESS_FBINFO(crtc1.vsync.wait));
 	init_waitqueue_head(&ACCESS_FBINFO(crtc2.vsync.wait));
+	ACCESS_FBINFO(crtc1.panpos) = -1;
 
 	err = initMatrox2(PMINFO b);
 	if (!err) {
@@ -2466,6 +2505,7 @@ module_exit(matrox_done);
 EXPORT_SYMBOL(matroxfb_register_driver);
 EXPORT_SYMBOL(matroxfb_unregister_driver);
 EXPORT_SYMBOL(matroxfb_wait_for_sync);
+EXPORT_SYMBOL(matroxfb_enable_irq);
 
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.

drivers/video/matrox/matroxfb_base.h

@@ -457,6 +457,7 @@ struct matrox_fb_info {
 		struct matrox_vsync	vsync;
 		unsigned int	pixclock;
 		int		mnp;
+		int		panpos;
 			      } crtc1;
 	struct {
 		struct matrox_vsync	vsync;

drivers/video/matrox/matroxfb_crtc2.c

@@ -148,7 +148,7 @@ static void matroxfb_dh_restore(struct matroxfb_dh_fb_info* m2info,
 	mga_outl(0x3C10, tmp);
 	ACCESS_FBINFO(hw).crtc2.ctl = tmp;
 
-	tmp = 0x0FFF0000;		/* line compare */
+	tmp = mt->VDisplay << 16;	/* line compare */
 	if (mt->sync & FB_SYNC_HOR_HIGH_ACT)
 		tmp |= 0x00000100;
 	if (mt->sync & FB_SYNC_VERT_HIGH_ACT)