i386/59854

[Eric Anholt]

The following reply was made to PR i386/59854; it has been noted by GNATS.

From: Eric Anholt <eta at lclark.edu>
To: gnats <freebsd-gnats-submit at FreeBSD.ORG>
Cc: green at FreeBSD.org
Subject: Re: i386/59854
Date: Sat, 21 Aug 2004 01:02:02 -0700

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 Attached is a patch that may help with AMD AGP issues.  It was
 improperly handling aperture sizes of 512M or higher, and the shutdown
 function (called as part of rebooting) may have been broken enough to
 confuse the hardware.  If people could give it a try and tell me if it
 improves the situation at all, that would be great.  I'm still doubtful
 it'll fix this PR, but it's a step.
 
 -- 
 Eric Anholt                                eta at lclark.edu          
 http://people.freebsd.org/~anholt/         anholt at FreeBSD.org
 
 
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 Index: agp_amd.c
 ===================================================================
 RCS file: /home/ncvs/src/sys/pci/agp_amd.c,v
 retrieving revision 1.21
 diff -u -u -r1.21 agp_amd.c
 --- agp_amd.c	16 Aug 2004 12:23:53 -0000	1.21
 +++ agp_amd.c	21 Aug 2004 07:48:31 -0000
 @@ -269,6 +269,12 @@
  	/* Enable the TLB and flush */
  	WRITE2(AGP_AMD751_STATUS,
  	       READ2(AGP_AMD751_STATUS) | AGP_AMD751_STATUS_GCE);
 +
 +	/* Setting bit 0 is required for the size to be valid. */
 +	pci_write_config(dev,
 +			 AGP_AMD751_APCTRL,
 +			 pci_read_config(dev, AGP_AMD751_APCTRL, 1) | 1, 1);
 +
  	AGP_FLUSH_TLB(dev);
  
  	return 0;
 @@ -313,7 +319,7 @@
  	/*
  	 * The aperture size is equal to 32M<<vas.
  	 */
 -	vas = (pci_read_config(dev, AGP_AMD751_APCTRL, 1) & 0x06) >> 1;
 +	vas = (pci_read_config(dev, AGP_AMD751_APCTRL, 1) & 0x0e) >> 1;
  	return (32*1024*1024) << vas;
  }
  
 @@ -321,6 +327,7 @@
  agp_amd_set_aperture(device_t dev, u_int32_t aperture)
  {
  	int vas;
 +	u_int32_t apctrl;
  
  	/*
  	 * Check for a power of two and make sure its within the
 @@ -331,15 +338,15 @@
  	    || aperture > 2U*1024*1024*1024)
  		return EINVAL;
  
 -	vas = ffs(aperture / 32*1024*1024) - 1;
 +	vas = ffs(aperture / (32*1024*1024)) - 1;
  	
  	/* 
  	 * While the size register is bits 1-3 of APCTRL, bit 0 must be
  	 * set for the size value to be 'valid'
  	 */
 +	apctrl = pci_read_config(dev, AGP_AMD751_APCTRL, 1);
  	pci_write_config(dev, AGP_AMD751_APCTRL,
 -			 (((pci_read_config(dev, AGP_AMD751_APCTRL, 1) & ~0x06)
 -			  | ((vas << 1) | 1))), 1);
 +			 (apctrl & ~0x0e) | (vas << 1) | 1, 1);
  
  	return 0;
  }
 
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