at86rf230: remove unnecessary spinlock

This spinlock isn't necessary because if we are in TX_ON/TX_ARET_ON
state the transceiver can't be interrupted e.g. by receiving a frame
when a SHR was detected. In this time the transceiver doesn't leave
the TX_ON/TX_ARET_ON state until the tx complete irq change the state
into RX_AACK_ON again. This means a receiving interrupt in state
TX_ON/TX_ARET_ON can't happen and is_tx is protected by transceiver.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index cc5efa149da181b031ae7b1be504d297922657dc..1278dd5ee18726653a0121078e00106a93a1a924 100644 (file)
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -25,7 +25,6 @@
 #include <linux/irq.h>
 #include <linux/gpio.h>
 #include <linux/delay.h>
-#include <linux/spinlock.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/at86rf230.h>
 #include <linux/regmap.h>
@@ -96,8 +95,6 @@ struct at86rf230_local {
        unsigned long cal_timeout;
        s8 max_frame_retries;
        bool is_tx;
-       /* spinlock for is_tx protection */
-       spinlock_t lock;
        u8 tx_retry;
        struct sk_buff *tx_skb;
        struct at86rf230_state_change tx;
@@ -878,10 +875,8 @@ at86rf230_rx_trac_check(void *context)
 static void
 at86rf230_irq_trx_end(struct at86rf230_local *lp)
 {
-       spin_lock(&lp->lock);
        if (lp->is_tx) {
                lp->is_tx = 0;
-               spin_unlock(&lp->lock);
 
                if (lp->tx_aret)
                        at86rf230_async_state_change(lp, &lp->irq,
@@ -894,7 +889,6 @@ at86rf230_irq_trx_end(struct at86rf230_local *lp)
                                                     at86rf230_tx_complete,
                                                     true);
        } else {
-               spin_unlock(&lp->lock);
                at86rf230_async_read_reg(lp, RG_TRX_STATE, &lp->irq,
                                         at86rf230_rx_trac_check, true);
        }
@@ -964,9 +958,7 @@ at86rf230_write_frame(void *context)
        u8 *buf = ctx->buf;
        int rc;
 
-       spin_lock(&lp->lock);
        lp->is_tx = 1;
-       spin_unlock(&lp->lock);
 
        buf[0] = CMD_FB | CMD_WRITE;
        buf[1] = skb->len + 2;
@@ -1698,7 +1690,6 @@ static int at86rf230_probe(struct spi_device *spi)
        if (rc < 0)
                goto free_dev;
 
-       spin_lock_init(&lp->lock);
        init_completion(&lp->state_complete);
 
        spi_set_drvdata(spi, lp);