Commit 5b876618 authored by Roland Vossen's avatar Roland Vossen Committed by Greg Kroah-Hartman
Browse files

staging: brcm80211: added clarification on softmac dma alignment 



Descriptor ring can only start at 8KB alignment, this requirement
is dictated by DMA hardware.

Reported-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarRoland Vossen <rvossen@broadcom.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 7d9e0b9a

drivers/staging/brcm80211/brcmsmac/dma.c

+6 −2
Original line number Diff line number Diff line
@@ -24,8 +24,8 @@ 
#include "dma.h"



/*

 * Each descriptor ring must be 8kB aligned, and fit within a

 * contiguous 8kB physical address.

 * DMA hardware requires each descriptor ring to be 8kB aligned, and fit within

 * a contiguous 8kB physical address.

 */

#define D64RINGALIGN_BITS	13

#define	D64MAXRINGSZ		(1 << D64RINGALIGN_BITS)
@@ -440,6 +440,10 @@ static bool _dma_descriptor_align(struct dma_info *di) 
	return true;

}



/*

 * Descriptor table must start at the DMA hardware dictated alignment, so

 * allocated memory must be large enough to support this requirement.

 */

static void *dma_alloc_consistent(struct pci_dev *pdev, uint size,

				  u16 align_bits, uint *alloced,

				  dma_addr_t *pap)