NFC: trf7970a: Clear possible spurious interrupt before transmitting
The trf7970a occasionally generates spurious interrupts
which can confuse the driver. To help alleviate this,
clear any interrupts by reading the 'IRQ Status Register'
before starting a new transaction.
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index b67946c..e7f22a4 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -1120,6 +1120,7 @@
char *prefix;
unsigned int len;
int ret;
+ u8 status;
dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
trf->state, timeout, skb->len);
@@ -1195,6 +1196,11 @@
len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
+ /* Clear possible spurious interrupt */
+ ret = trf7970a_read_irqstatus(trf, &status);
+ if (ret)
+ goto out_err;
+
ret = trf7970a_transmit(trf, skb, len);
if (ret) {
kfree_skb(trf->rx_skb);