ath6kl: Fix system freeze under heavy data load

Patch "ath6kl: Fix buffer alignment for scatter-gather write" does
memmove for a length (scat_req->scat_list[i].len) which is not the
actual length of data that is suppossed to be moved. The right
lengh is packet->act_len + HTC_HDR_LENGTH. Using wrong length
for data move during buffer alignment causes system freeze after
the following WARN_ON and sometimes target assert.

WARNING: at drivers/net/wireless/ath/ath6kl/main.c:771 ath6k_credit_distribute+0x196/0x1a0
 [<ffffffffa051cf5f>] ath6kl_htc_rxmsg_pending_handler+0x83f/0xe00 [ath6kl]
 [<ffffffff8104a743>] ? __wake_up+0x53/0x70
 [<ffffffffa0518b18>] ath6kldev_intr_bh_handler+0x188/0x650 [ath6kl]
 [<ffffffffa052d316>] ath6kl_sdio_irq_handler+0x36/0x80 [ath6kl]
 [<ffffffff81492b3c>] sdio_irq_thread+0xfc/0x360
 [<ffffffff81051c52>] ? default_wake_function+0x12/0x20
 [<ffffffff81492a40>] ? sdio_claim_irq+0x220/0x220
 [<ffffffff81080c36>] kthread+0x96/0xa0
 [<ffffffff815b9fb4>] kernel_thread_helper+0x4/0x10
 [<ffffffff81080ba0>] ? kthread_worker_fn+0x190/0x190
 [<ffffffff815b9fb0>] ? gs_change+0x13/0x13

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath6kl/htc.c b/drivers/net/wireless/ath/ath6kl/htc.c
index 2001660..dc575a8 100644 (file)
--- a/drivers/net/wireless/ath/ath6kl/htc.c
+++ b/drivers/net/wireless/ath/ath6kl/htc.c
@@ -22,6 +22,17 @@
 
 #define CALC_TXRX_PADDED_LEN(dev, len)  (__ALIGN_MASK((len), (dev)->block_mask))
 
+static void ath6kl_htc_buf_align(u8 **buf, unsigned long len)
+{
+       u8 *align_addr;
+
+       if (!IS_ALIGNED((unsigned long) *buf, 4)) {
+               align_addr = PTR_ALIGN(*buf - 4, 4);
+               memmove(align_addr, *buf, len);
+               *buf = align_addr;
+       }
+}
+
 static void htc_prep_send_pkt(struct htc_packet *packet, u8 flags, int ctrl0,
                              int ctrl1)
 {
@@ -391,6 +402,9 @@ static int htc_setup_send_scat_list(struct htc_target *target,
                htc_prep_send_pkt(packet,
                                packet->info.tx.flags | HTC_FLAGS_SEND_BUNDLE,
                                cred_pad, packet->info.tx.seqno);
+               /* Make sure the buffer is 4-byte aligned */
+               ath6kl_htc_buf_align(&packet->buf,
+                                    packet->act_len + HTC_HDR_LENGTH);
                scat_req->scat_list[i].buf = packet->buf;
                scat_req->scat_list[i].len = len;
 

diff --git a/drivers/net/wireless/ath/ath6kl/sdio.c b/drivers/net/wireless/ath/ath6kl/sdio.c
index 852a0cc..0cce801 100644 (file)
--- a/drivers/net/wireless/ath/ath6kl/sdio.c
+++ b/drivers/net/wireless/ath/ath6kl/sdio.c
@@ -128,17 +128,6 @@ static int ath6kl_sdio_func0_cmd52_wr_byte(struct mmc_card *card,
        return mmc_wait_for_cmd(card->host, &io_cmd, 0);
 }
 
-static void ath6kl_sdio_buf_align(u8 **buf, unsigned long len)
-{
-       u8 *align_addr;
-
-       if (!IS_ALIGNED((unsigned long) *buf, 4)) {
-               align_addr = PTR_ALIGN(*buf - 4, 4);
-               memmove(align_addr, *buf, len);
-               *buf = align_addr;
-       }
-}
-
 static int ath6kl_sdio_io(struct sdio_func *func, u32 request, u32 addr,
                          u8 *buf, u32 len)
 {
@@ -224,10 +213,6 @@ static void ath6kl_sdio_setup_scat_data(struct hif_scatter_req *scat_req,
 
        /* assemble SG list */
        for (i = 0; i < scat_req->scat_entries; i++, sg++) {
-               /* No header is added to rx buf, so it shoule be aligned */
-               if (data->flags == MMC_DATA_WRITE)
-                       ath6kl_sdio_buf_align(&scat_req->scat_list[i].buf,
-                                             scat_req->scat_list[i].len);
                ath6kl_dbg(ATH6KL_DBG_SCATTER, "%d: addr:0x%p, len:%d\n",
                           i, scat_req->scat_list[i].buf,
                           scat_req->scat_list[i].len);

diff --git a/drivers/net/wireless/ath/ath6kl/txrx.c b/drivers/net/wireless/ath/ath6kl/txrx.c
index ba1350d..ba33370 100644 (file)
--- a/drivers/net/wireless/ath/ath6kl/txrx.c
+++ b/drivers/net/wireless/ath/ath6kl/txrx.c
@@ -689,7 +689,8 @@ void ath6kl_rx_refill(struct htc_target *target, enum htc_endpoint_id endpoint)
                        break;
 
                packet = (struct htc_packet *) skb->head;
-               skb->data = PTR_ALIGN(skb->data - 4, 4);
+               if (!IS_ALIGNED((unsigned long) skb->data, 4))
+                       skb->data = PTR_ALIGN(skb->data - 4, 4);
                set_htc_rxpkt_info(packet, skb, skb->data,
                                ATH6KL_BUFFER_SIZE, endpoint);
                list_add_tail(&packet->list, &queue);
@@ -710,7 +711,8 @@ void ath6kl_refill_amsdu_rxbufs(struct ath6kl *ar, int count)
                        return;
 
                packet = (struct htc_packet *) skb->head;
-               skb->data = PTR_ALIGN(skb->data - 4, 4);
+               if (!IS_ALIGNED((unsigned long) skb->data, 4))
+                       skb->data = PTR_ALIGN(skb->data - 4, 4);
                set_htc_rxpkt_info(packet, skb, skb->data,
                                   ATH6KL_AMSDU_BUFFER_SIZE, 0);
                spin_lock_bh(&ar->lock);