Re: [PATCH] b43: Changes to enable BCM4311 rev 02 with wireless core revision 13

[Michael Buesch <mb@bu3sch.de>]

On Wednesday 21 November 2007 21:02:25 Larry Finger wrote:
> Michael Buesch wrote:
> > On Wednesday 21 November 2007 20:31:53 Larry Finger wrote:
> >> The BCM94311MCG rev 02 chip has an 802.11 core with revision 13 an=
d
> >> has not been supported until now. The changes include the followin=
g:
> >>
> >> (1) Add the 802.11 rev 13 device to the ssb_device_id table to loa=
d b43.
> >> (2) Add PHY revision 9 to the supported list.
> >> (3) Fix 64-bit addressing errors.
> >> (4) Remove some magic numbers in the DMA setup.
> >>
> >> The DMA implementation for this chip supports full 64-bit addressi=
ng with
> >> one exception. Whenever the Descriptor Ring Buffer is in high memo=
ry, a
> >> fatal DMA error occurs. This problem was not present in 2.6.24-rc2=
 due
> >> to code to "Bias the placement of kernel pages at lower PFNs". Whe=
n
> >> commit 44048d70 reverted that code, the DMA error appeared. As a "=
fix",
> >> use the GFP_DMA flag when allocating the buffer for 64-bit DMA. At=
 present,
> >> this problem is thought to arise from a hardware error. The presen=
t driver
> >> allocates one ring buffer for RX and six for TX; however, only one=
 of the
> >> TX buffers is used. To minimize any system impact associated with =
using low
> >> memory, this patch removes the allocation of the unused buffers.
> >>
> >> This patch has been tested by C=C3=A9dric Caumont <icare40@hotmail=
=2Ecom>.
> >>
> >=20
> >> @@ -954,19 +955,21 @@ int b43_dma_init(struct b43_wldev *dev)
> >> =20
> >>  	err =3D -ENOMEM;
> >>  	/* setup TX DMA channels. */
> >> -	ring =3D b43_setup_dmaring(dev, 0, 1, dma64);
> >> +	ring =3D b43_setup_dmaring(dev, 1, 1, dma64);
> >>  	if (!ring)
> >>  		goto out;
> >> -	dma->tx_ring0 =3D ring;
> >> +	dma->tx_ring1 =3D ring;
> >> =20
> >> -	ring =3D b43_setup_dmaring(dev, 1, 1, dma64);
> >> +	/* The driver only uses ring1 for TX - skip setup for the rest *=
/
> >> +#if 0
> >=20
> > NACK.
>=20
> Are you NACKing the "if 0" or the elimination of the unused TX rings?=
 Perhaps we could have

Both

> 	if (ring->dma64)
> 		goto out;

No,
I am going to submit patches to enable use of multiple TX queues.
See my quilt series.
Simply don't change current behaviour. ;)

The only reason for me holding these patches back is that I could
not sufficiently test them yet.

--=20
Greetings Michael.
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