From: Cindy H Kao <[email protected]> i2400ms_bus_bm_wait_for_ack() causes a race condition. It happens because this function clears i2400ms->bm_ack_size before waiting for an interrupt, which is set by the interrupt service routine i2400ms_rx() to indicate reception and size of received data; thus, if the interrupt came right before the clearing/waiting, it is lost.
The fix is clear the bm_ack_size to -EINPROGRESS before we are enabling the RX interrupt configuration in i2400ms_rx_setup(). Then everytime when the interrupt service routine i2400ms_rx() is invoked during bootmode, bm_ack_size is updated with the actual rx_size and it is cleared to -EINPROGRESS again after the RX data is handled. Signed-off-by: Cindy H Kao <[email protected]> Signed-off-by: Inaky Perez-Gonzalez <[email protected]> --- drivers/net/wimax/i2400m/sdio-fw.c | 8 ++++---- drivers/net/wimax/i2400m/sdio-rx.c | 7 +++++++ 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/net/wimax/i2400m/sdio-fw.c b/drivers/net/wimax/i2400m/sdio-fw.c index 7d6ec0f..c8dc538 100644 --- a/drivers/net/wimax/i2400m/sdio-fw.c +++ b/drivers/net/wimax/i2400m/sdio-fw.c @@ -177,10 +177,6 @@ ssize_t i2400ms_bus_bm_wait_for_ack(struct i2400m *i2400m, d_fnstart(5, dev, "(i2400m %p ack %p size %zu)\n", i2400m, ack, ack_size); - spin_lock(&i2400m->rx_lock); - i2400ms->bm_ack_size = -EINPROGRESS; - spin_unlock(&i2400m->rx_lock); - result = wait_event_timeout(i2400ms->bm_wfa_wq, i2400ms->bm_ack_size != -EINPROGRESS, 2 * HZ); @@ -199,6 +195,10 @@ ssize_t i2400ms_bus_bm_wait_for_ack(struct i2400m *i2400m, size = min(ack_size, i2400ms->bm_ack_size); memcpy(ack, i2400m->bm_ack_buf, size); } + /* + * Remember always to clear the bm_ack_size to -EINPROGRESS + * after the RX data is processed + */ i2400ms->bm_ack_size = -EINPROGRESS; spin_unlock(&i2400m->rx_lock); diff --git a/drivers/net/wimax/i2400m/sdio-rx.c b/drivers/net/wimax/i2400m/sdio-rx.c index 321bead..f6ca51a 100644 --- a/drivers/net/wimax/i2400m/sdio-rx.c +++ b/drivers/net/wimax/i2400m/sdio-rx.c @@ -234,6 +234,13 @@ int i2400ms_rx_setup(struct i2400ms *i2400ms) init_waitqueue_head(&i2400ms->bm_wfa_wq); spin_lock(&i2400m->rx_lock); i2400ms->bm_wait_result = -EINPROGRESS; + /* + * Before we are about to enable the RX interrupt, make sure + * bm_ack_size is cleared to -EINPROGRESS which indicates + * no RX interrupt happened yet or the previous interrupt + * has been handled, we are ready to take the new interrupt + */ + i2400ms->bm_ack_size = -EINPROGRESS; spin_unlock(&i2400m->rx_lock); sdio_claim_host(func); -- 1.6.2.5 _______________________________________________ wimax mailing list [email protected] http://lists.linuxwimax.org/listinfo/wimax
