Re: [PATCH] drm/nouveau/bios: fix offset calculation for BMPv1 bioses

[Ben Skeggs <bskeggs@redhat.com>]

----- Original Message -----
> From: "Ilia Mirkin" <imirkin@alum.mit.edu>
> To: "Ben Skeggs" <bskeggs@redhat.com>
> Cc: dri-devel@lists.freedesktop.org, "Ilia Mirkin" <imirkin@alum.mit.edu>
> Sent: Wednesday, 8 January, 2014 3:33:59 AM
> Subject: [PATCH] drm/nouveau/bios: fix offset calculation for BMPv1 bioses
> 
> The only BIOS on record that needs the 14 offset has a bios major
> version 2 but BMP version 1.01. Another bunch of BIOSes that need the 18
> offset have BMP version 2.01 or 5.01 or higher. So instead of looking at the
> bios major version, look at the BMP version. BIOSes with BMP version 0
> do not contain a detectable script, so always return 0 for them.
I've merged the patch, thanks.

> 
> See https://bugs.freedesktop.org/show_bug.cgi?id=68835
> 
> Reported-by: Mauro Molinari <mauromol@tiscali.it>
> Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
> ---
> 
> Unfortunately the bug reporter doesn't really know how to compile kernels and
> my bet is that the system his NV04 is in isn't exactly top-of-the-line, so a
> kernel compile would take forever.
> 
> I've made similar changes in nvbios, and it seems to now handle every
> nv04/nv05 bios in our repo, in addition to Mauro's, so I think these changes
> should be safe-ish. However I'm not tagging for stable yet, in case things
> don't pan out the way I expected. If Mauro tests a kernel with this and all's
> well, then I'll send a separate request to stable-ify this patch.
> 
> I'm betting that some old code used to check the bmp_version_major against 2,
> but that got changed to bios major in one of the rewrites, although I didn't
> go digging.
You are correct.  I confirmed this this morning.

> 
>  drivers/gpu/drm/nouveau/core/subdev/bios/init.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
> b/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
> index 9f5b81e..df1b1b4 100644
> --- a/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
> +++ b/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
> @@ -365,13 +365,13 @@ static u16
>  init_script(struct nouveau_bios *bios, int index)
>  {
>  	struct nvbios_init init = { .bios = bios };
> -	u16 data;
> +	u16 bmp_ver = bmp_version(bios), data;
>  
> -	if (bmp_version(bios) && bmp_version(bios) < 0x0510) {
> -		if (index > 1)
> +	if (bmp_ver && bmp_ver < 0x0510) {
> +		if (index > 1 || bmp_ver < 0x0100)
>  			return 0x0000;
>  
> -		data = bios->bmp_offset + (bios->version.major < 2 ? 14 : 18);
> +		data = bios->bmp_offset + (bmp_ver < 0x0200 ? 14 : 18);
>  		return nv_ro16(bios, data + (index * 2));
>  	}
>  
> --
> 1.8.3.2
> 
>