Return-path: Received: from mail-ew0-f46.google.com ([209.85.215.46]:34995 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757052Ab0KMSOV (ORCPT ); Sat, 13 Nov 2010 13:14:21 -0500 Received: by mail-ew0-f46.google.com with SMTP id 8so221945ewy.19 for ; Sat, 13 Nov 2010 10:14:20 -0800 (PST) From: Ivo van Doorn To: "John W. Linville" Subject: [PATCH 7/9] rt2x00: Fix rt2800 USB TX Path DMA issue Date: Sat, 13 Nov 2010 19:11:46 +0100 Cc: linux-wireless@vger.kernel.org, users@rt2x00.serialmonkey.com References: <201011131908.15595.IvDoorn@gmail.com> <201011131910.55175.IvDoorn@gmail.com> <201011131911.22874.IvDoorn@gmail.com> In-Reply-To: <201011131911.22874.IvDoorn@gmail.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Message-Id: <201011131911.47346.IvDoorn@gmail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: From: RA-Jay Hung rt2800usb chips need to add 1~3 bytes zero padding after each 802.11 header & payload, and at the end need to add 4 bytes zero padding whether doing TX bulk aggregation or not, TXINFO_W0_USB_DMA_TX_PKT_LEN in TXINFO must include 1-3 bytes padding after 802.11 header & payload but do not include 4 bytes end zero padding. In rt2800usb_get_tx_data_len do not consider multiple of the USB packet size case, sometimes this will cause USB DMA problem. Signed-off-by: RA-Jay Hung Signed-off-by: Ivo van Doorn --- drivers/net/wireless/rt2x00/rt2800usb.c | 39 ++++++++++++++++++++---------- 1 files changed, 26 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c index 2933bf1..935b76d 100644 --- a/drivers/net/wireless/rt2x00/rt2800usb.c +++ b/drivers/net/wireless/rt2x00/rt2800usb.c @@ -307,8 +307,14 @@ static void rt2800usb_write_tx_desc(struct queue_entry *entry, * Initialize TXINFO descriptor */ rt2x00_desc_read(txi, 0, &word); + + /* + * The size of TXINFO_W0_USB_DMA_TX_PKT_LEN is + * TXWI + 802.11 header + L2 pad + payload + pad, + * so need to decrease size of TXINFO and USB end pad. + */ rt2x00_set_field32(&word, TXINFO_W0_USB_DMA_TX_PKT_LEN, - entry->skb->len - TXINFO_DESC_SIZE); + entry->skb->len - TXINFO_DESC_SIZE - 4); rt2x00_set_field32(&word, TXINFO_W0_WIV, !test_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags)); rt2x00_set_field32(&word, TXINFO_W0_QSEL, 2); @@ -326,22 +332,29 @@ static void rt2800usb_write_tx_desc(struct queue_entry *entry, skbdesc->desc_len = TXINFO_DESC_SIZE + TXWI_DESC_SIZE; } -/* - * TX data initialization - */ -static int rt2800usb_get_tx_data_len(struct queue_entry *entry) +static void rt2800usb_write_tx_data(struct queue_entry *entry, + struct txentry_desc *txdesc) { - int length; + u8 padding_len; /* - * The length _must_ include 4 bytes padding, - * it should always be multiple of 4, - * but it must _not_ be a multiple of the USB packet size. + * pad(1~3 bytes) is added after each 802.11 payload. + * USB end pad(4 bytes) is added at each USB bulk out packet end. + * TX frame format is : + * | TXINFO | TXWI | 802.11 header | L2 pad | payload | pad | USB end pad | + * |<------------- tx_pkt_len ------------->| */ - length = roundup(entry->skb->len + 4, 4); - length += (4 * !(length % entry->queue->usb_maxpacket)); + rt2800_write_tx_data(entry, txdesc); + padding_len = roundup(entry->skb->len + 4, 4) - entry->skb->len; + memset(skb_put(entry->skb, padding_len), 0, padding_len); +} - return length; +/* + * TX data initialization + */ +static int rt2800usb_get_tx_data_len(struct queue_entry *entry) +{ + return entry->skb->len; } /* @@ -579,7 +592,7 @@ static const struct rt2x00lib_ops rt2800usb_rt2x00_ops = { .link_tuner = rt2800_link_tuner, .watchdog = rt2800usb_watchdog, .write_tx_desc = rt2800usb_write_tx_desc, - .write_tx_data = rt2800_write_tx_data, + .write_tx_data = rt2800usb_write_tx_data, .write_beacon = rt2800_write_beacon, .get_tx_data_len = rt2800usb_get_tx_data_len, .kick_tx_queue = rt2x00usb_kick_tx_queue, -- 1.7.2.3