Commit 954de914 authored by Samuel Thibault's avatar Samuel Thibault Committed by Linus Torvalds
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[PATCH] vgacon: fix doublescan mode

When doublescan mode is in use, scanlines must be doubled.

Thanks to Jason Dravet <> for reporting and testing.
Signed-off-by: default avatarSamuel Thibault <>
Cc: <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent b8b0af24
......@@ -503,10 +503,16 @@ static int vgacon_doresize(struct vc_data *c,
unsigned long flags;
unsigned int scanlines = height * c->vc_font.height;
u8 scanlines_lo, r7, vsync_end, mode;
u8 scanlines_lo, r7, vsync_end, mode, max_scan;
spin_lock_irqsave(&vga_lock, flags);
outb_p(VGA_CRTC_MAX_SCAN, vga_video_port_reg);
max_scan = inb_p(vga_video_port_val);
if (max_scan & 0x80)
scanlines <<= 1;
outb_p(VGA_CRTC_MODE, vga_video_port_reg);
mode = inb_p(vga_video_port_val);
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