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Commit a3c5d8fb authored by Christophe Ricard's avatar Christophe Ricard Committed by Samuel Ortiz
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NFC: st21nfca: Synchronize i2c Tx and Rx path 



Stabilize communication by using a mutex.
This avoids running a write transaction during a read retry or a read
transaction during a write retry.

Signed-off-by: default avatarChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent c97ffdbf

drivers/nfc/st21nfca/i2c.c

+6 −0
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ struct st21nfca_i2c_phy { 
	 * and prevents normal operation.

	 */

	int hard_fault;

	struct mutex phy_lock;

};

static u8 len_seq[] = { 13, 24, 15, 29 };

static u16 wait_tab[] = { 2, 3, 5, 15, 20, 40};
@@ -245,11 +246,13 @@ static int st21nfca_hci_i2c_write(void *phy_id, struct sk_buff *skb) 
	 * Manage sleep mode

	 * Try 3 times to send data with delay between each

	 */

	mutex_lock(&phy->phy_lock);

	for (i = 0; i < ARRAY_SIZE(wait_tab) && r < 0; i++) {

		r = i2c_master_send(client, tmp, j);

		if (r < 0)

			msleep(wait_tab[i]);

	}

	mutex_unlock(&phy->phy_lock);



	if (r >= 0) {

		if (r != j)
@@ -375,11 +378,13 @@ static int st21nfca_hci_i2c_read(struct st21nfca_i2c_phy *phy, 
		 * RF or SWP interface

		 */

		r = 0;

		mutex_lock(&phy->phy_lock);

		for (i = 0; i < ARRAY_SIZE(wait_tab) && r <= 0; i++) {

			r = i2c_master_recv(client, buf, len);

			if (r < 0)

				msleep(wait_tab[i]);

		}

		mutex_unlock(&phy->phy_lock);



		if (r != len) {

			phy->current_read_len = 0;
@@ -575,6 +580,7 @@ static int st21nfca_hci_i2c_probe(struct i2c_client *client, 


	phy->current_read_len = 0;

	phy->crc_trials = 0;

	mutex_init(&phy->phy_lock);

	i2c_set_clientdata(client, phy);



	pdata = client->dev.platform_data;