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| author | Christophe Ricard <christophe.ricard@gmail.com> | 2014-04-24 23:19:34 +0200 |
|---|---|---|
| committer | Samuel Ortiz <sameo@linux.intel.com> | 2014-05-05 01:01:23 +0200 |
| commit | a3c5d8fb7ffa8850f3d2fc01e1dde0709a3954f9 (patch) | |
| tree | b8cc659914079b6811af7c393ad6664359a0fd70 /drivers/nfc | |
| parent | NFC: st21nfca: Improved i2c Rx data correctness check (diff) | |
| download | linux-a3c5d8fb7ffa8850f3d2fc01e1dde0709a3954f9.tar.xz linux-a3c5d8fb7ffa8850f3d2fc01e1dde0709a3954f9.zip | |
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: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/nfc')
| -rw-r--r-- | drivers/nfc/st21nfca/i2c.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/nfc/st21nfca/i2c.c b/drivers/nfc/st21nfca/i2c.c index 48f8e23fc321..b64d8e2e429a 100644 --- a/drivers/nfc/st21nfca/i2c.c +++ b/drivers/nfc/st21nfca/i2c.c @@ -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; |