hgafb: resource management fix

hgafb: resource management fix

[Krzysztof Helt]

From: Krzysztof Helt <krzysztof.h1@wp.pl>

Release ports which are requested during detection
which are not freed if there is no hga card.
Otherwise there is a crash during cat /proc/ioports command. 

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>

--- linux-rc2/drivers/video/hgafb.c	2008-06-02 20:09:20.139779110 +0200
+++ linux-new/drivers/video/hgafb.c	2008-06-02 20:01:45.030230800 +0200
@@ -279,7 +279,7 @@ static void hga_blank(int blank_mode)
 
 static int __init hga_card_detect(void)
 {
-	int count=0;
+	int count = 0;
 	void __iomem *p, *q;
 	unsigned short p_save, q_save;
 
@@ -303,20 +303,18 @@ static int __init hga_card_detect(void)
 	writew(0x55aa, p); if (readw(p) == 0x55aa) count++;
 	writew(p_save, p);
 
-	if (count != 2) {
-		return 0;
-	}
+	if (count != 2)
+		goto error;
 
 	/* Ok, there is definitely a card registering at the correct
 	 * memory location, so now we do an I/O port test.
 	 */
 	
-	if (!test_hga_b(0x66, 0x0f)) {	    /* cursor low register */
-		return 0;
-	}
-	if (!test_hga_b(0x99, 0x0f)) {     /* cursor low register */
-		return 0;
-	}
+	if (!test_hga_b(0x66, 0x0f))	    /* cursor low register */
+		goto error;
+
+	if (!test_hga_b(0x99, 0x0f))     /* cursor low register */
+		goto error;
 
 	/* See if the card is a Hercules, by checking whether the vsync
 	 * bit of the status register is changing.  This test lasts for
@@ -331,7 +329,7 @@ static int __init hga_card_detect(void)
 	}
 
 	if (p_save == q_save) 
-		return 0;
+		goto error;
 
 	switch (inb_p(HGA_STATUS_PORT) & 0x70) {
 		case 0x10:
@@ -348,6 +346,12 @@ static int __init hga_card_detect(void)
 			break;
 	}
 	return 1;
+error:
+	if (release_io_ports)
+		release_region(0x3b0, 12);
+	if (release_io_port)
+		release_region(0x3bf, 1);
+	return 0;
 }
 
 /**

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Re: hgafb: resource management fix

[Andrew Morton]

On Sun, 8 Jun 2008 00:06:12 +0200 Krzysztof Helt <krzysztof.h1@poczta.fm> wrote:

> Release ports which are requested during detection
> which are not freed if there is no hga card.
> Otherwise there is a crash during cat /proc/ioports command. 

erk.

I'll assume that this is needed in both 2.6.26 and 2.6.25.x.

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