Commit b05b7c7c authored by Muhammad Hamza Farooq's avatar Muhammad Hamza Farooq Committed by Greg Kroah-Hartman
Browse files

ti-st: use worker instead of calling st_int_write in wake up 



The wake up method is called with the port lock held. The st_int_write
method calls port->ops->write with tries to acquire the lock again,
causing CPU to wait infinitely. Right way to do is to write data to port
in worker thread.

Signed-off-by: default avatarMuhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: default avatarJacob Siverskog <jacob@teenage.engineering>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f97ef759

drivers/misc/ti-st/st_core.c

+16 −2
Original line number Diff line number Diff line
@@ -460,6 +460,13 @@ static void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb) 
 * - TTY layer when write's finished

 * - st_write (in context of the protocol stack)

 */

static void work_fn_write_wakeup(struct work_struct *work)

{

	struct st_data_s *st_gdata = container_of(work, struct st_data_s,

			work_write_wakeup);



	st_tx_wakeup((void *)st_gdata);

}

void st_tx_wakeup(struct st_data_s *st_data)

{

	struct sk_buff *skb;
@@ -812,8 +819,12 @@ static void st_tty_wakeup(struct tty_struct *tty) 
	/* don't do an wakeup for now */

	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);



	/* call our internal wakeup */

	st_tx_wakeup((void *)st_gdata);

	/*

	 * schedule the internal wakeup instead of calling directly to

	 * avoid lockup (port->lock needed in tty->ops->write is

	 * already taken here

	 */

	schedule_work(&st_gdata->work_write_wakeup);

}



static void st_tty_flush_buffer(struct tty_struct *tty)
@@ -881,6 +892,9 @@ int st_core_init(struct st_data_s **core_data) 
			pr_err("unable to un-register ldisc");

		return err;

	}



	INIT_WORK(&st_gdata->work_write_wakeup, work_fn_write_wakeup);



	*core_data = st_gdata;

	return 0;

}

include/linux/ti_wilink_st.h

+1 −0
Original line number Diff line number Diff line
@@ -158,6 +158,7 @@ struct st_data_s { 
	unsigned long ll_state;

	void *kim_data;

	struct tty_struct *tty;

	struct work_struct work_write_wakeup;

};



/*

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