Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5b45bfe5 authored by Cindy H Kao's avatar Cindy H Kao Committed by Inaky Perez-Gonzalez
Browse files

wimax/i2400m: fix the bootmode RX deadlock in SDIO driver 



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: default avatarCindy H Kao <cindy.h.kao@intel.com>
Signed-off-by: default avatarInaky Perez-Gonzalez <inaky@linux.intel.com>
parent 663ebb4a

drivers/net/wimax/i2400m/sdio-fw.c

+4 −4
Original line number Diff line number Diff line
@@ -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);

drivers/net/wimax/i2400m/sdio-rx.c

+7 −0
Original line number Diff line number Diff line
@@ -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);