iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

wil6210: fix subtle race in wil_tx_vring

Browse Source 
Finish all SW context modifications prior to notifying hardware

It used to be race condition: if HW finish Tx and issue Tx completion IRQ very fast,
prior to SW context update in wil_tx_vring, Tx completion will mis-handle descriptor, as
SW part will have no skb pointer stored.

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Vladimir Kondratiev 2013-07-11 18:03:41 +03:00 committed by John W. Linville
parent f88f113a54
commit 6cdadd4dc7
1 changed files with 6 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/net/wireless/ath/wil6210/txrx.c
View File

@ -712,6 +712,12 @@ static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
*_d = *d;
/* hold reference to skb
* to prevent skb release before accounting
* in case of immediate "tx done"
*/
vring->ctx[i].skb = skb_get(skb);
wil_hex_dump_txrx("Tx ", DUMP_PREFIX_NONE, 32, 4,
(const void *)d, sizeof(*d), false);
@ -720,11 +726,6 @@ static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
wil_dbg_txrx(wil, "Tx swhead %d -> %d\n", swhead, vring->swhead);
trace_wil6210_tx(vring_index, swhead, skb->len, nr_frags);
iowrite32(vring->swhead, wil->csr + HOSTADDR(vring->hwtail));
/* hold reference to skb
* to prevent skb release before accounting
* in case of immediate "tx done"
*/
vring->ctx[i].skb = skb_get(skb);
return 0;
dma_error: