The s5p-cec driver returned CEC_TX_STATUS_ERROR for the NACK condition.
Some digging into the datasheet uncovered the S5P_CEC_TX_STAT1 register where
bit 0 indicates if the transmit was nacked or not.
Use this to return the correct CEC_TX_STATUS_NACK status to userspace.
This was the only driver that couldn't tell a NACK from another error, and
that was very unusual. And a potential problem for applications as well.
Tested with my Odroid-U3.
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
diff --git a/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c b/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
index 1edf667d562a..146ae6f25cdb 100644
--- a/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
+++ b/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
@@ -172,7 +172,8 @@ u32 s5p_cec_get_status(struct s5p_cec_dev *cec)
{
u32 status = 0;
- status = readb(cec->reg + S5P_CEC_STATUS_0);
+ status = readb(cec->reg + S5P_CEC_STATUS_0) & 0xf;
+ status |= (readb(cec->reg + S5P_CEC_TX_STAT1) & 0xf) << 4;
status |= readb(cec->reg + S5P_CEC_STATUS_1) << 8;
status |= readb(cec->reg + S5P_CEC_STATUS_2) << 16;
status |= readb(cec->reg + S5P_CEC_STATUS_3) << 24;
diff --git a/drivers/media/platform/s5p-cec/s5p_cec.c b/drivers/media/platform/s5p-cec/s5p_cec.c
index 9f92e90b99fc..316736610f2d 100644
--- a/drivers/media/platform/s5p-cec/s5p_cec.c
+++ b/drivers/media/platform/s5p-cec/s5p_cec.c
@@ -92,7 +92,10 @@ static irqreturn_t s5p_cec_irq_handler(int irq, void *priv)
dev_dbg(cec->dev, "irq received\n");
if (status & CEC_STATUS_TX_DONE) {
- if (status & CEC_STATUS_TX_ERROR) {
+ if (status & CEC_STATUS_TX_NACK) {
+ dev_dbg(cec->dev, "CEC_STATUS_TX_NACK set\n");
+ cec->tx = STATE_NACK;
+ } else if (status & CEC_STATUS_TX_ERROR) {
dev_dbg(cec->dev, "CEC_STATUS_TX_ERROR set\n");
cec->tx = STATE_ERROR;
} else {
@@ -135,6 +138,12 @@ static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
cec->tx = STATE_IDLE;
break;
+ case STATE_NACK:
+ cec_transmit_done(cec->adap,
+ CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_NACK,
+ 0, 1, 0, 0);
+ cec->tx = STATE_IDLE;
+ break;
case STATE_ERROR:
cec_transmit_done(cec->adap,
CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,
diff --git a/drivers/media/platform/s5p-cec/s5p_cec.h b/drivers/media/platform/s5p-cec/s5p_cec.h
index 7015845c1caa..fd6804370d98 100644
--- a/drivers/media/platform/s5p-cec/s5p_cec.h
+++ b/drivers/media/platform/s5p-cec/s5p_cec.h
@@ -36,6 +36,7 @@
#define CEC_STATUS_TX_TRANSFERRING (1 << 1)
#define CEC_STATUS_TX_DONE (1 << 2)
#define CEC_STATUS_TX_ERROR (1 << 3)
+#define CEC_STATUS_TX_NACK (1 << 4)
#define CEC_STATUS_TX_BYTES (0xFF << 8)
#define CEC_STATUS_RX_RUNNING (1 << 16)
#define CEC_STATUS_RX_RECEIVING (1 << 17)
@@ -56,6 +57,7 @@ enum cec_state {
STATE_IDLE,
STATE_BUSY,
STATE_DONE,
+ STATE_NACK,
STATE_ERROR
};
