Unverified Commit e9c9481f authored by Dom Cobley's avatar Dom Cobley Committed by Maxime Ripard
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drm/vc4: hdmi: Fix register offset with longer CEC messages 



The code prior to 311e305f ("drm/vc4: hdmi: Implement a register
layout abstraction") was relying on the fact that the register offset
was incremented by 4 for each readl call. That worked since the register
width is 4 bytes.

However, since that commit the HDMI_READ macro is now taking an enum,
and the offset doesn't increment by 4 but 1 now. Divide the index by 4
to fix this.

Fixes: 311e305f ("drm/vc4: hdmi: Implement a register layout abstraction")
Reviewed-by: default avatarDave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: default avatarDom Cobley <popcornmix@gmail.com>
Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
Acked-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Tested-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111142309.193441-4-maxime@cerno.tech
parent 7155334f

drivers/gpu/drm/vc4/vc4_hdmi.c

+15 −2
Original line number Diff line number Diff line
@@ -1443,13 +1443,20 @@ static irqreturn_t vc4_cec_irq_handler_thread(int irq, void *priv) 


static void vc4_cec_read_msg(struct vc4_hdmi *vc4_hdmi, u32 cntrl1)

{

	struct drm_device *dev = vc4_hdmi->connector.dev;

	struct cec_msg *msg = &vc4_hdmi->cec_rx_msg;

	unsigned int i;



	msg->len = 1 + ((cntrl1 & VC4_HDMI_CEC_REC_WRD_CNT_MASK) >>

					VC4_HDMI_CEC_REC_WRD_CNT_SHIFT);



	if (msg->len > 16) {

		drm_err(dev, "Attempting to read too much data (%d)\n", msg->len);

		return;

	}



	for (i = 0; i < msg->len; i += 4) {

		u32 val = HDMI_READ(HDMI_CEC_RX_DATA_1 + i);

		u32 val = HDMI_READ(HDMI_CEC_RX_DATA_1 + (i >> 2));



		msg->msg[i] = val & 0xff;

		msg->msg[i + 1] = (val >> 8) & 0xff;
@@ -1542,11 +1549,17 @@ static int vc4_hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts, 
				      u32 signal_free_time, struct cec_msg *msg)

{

	struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);

	struct drm_device *dev = vc4_hdmi->connector.dev;

	u32 val;

	unsigned int i;



	if (msg->len > 16) {

		drm_err(dev, "Attempting to transmit too much data (%d)\n", msg->len);

		return -ENOMEM;

	}



	for (i = 0; i < msg->len; i += 4)

		HDMI_WRITE(HDMI_CEC_TX_DATA_1 + i,

		HDMI_WRITE(HDMI_CEC_TX_DATA_1 + (i >> 2),

			   (msg->msg[i]) |

			   (msg->msg[i + 1] << 8) |

			   (msg->msg[i + 2] << 16) |