From: Dom Cobley <popcornmix@xxxxxxxxx> [ Upstream commit 4a59ed546c0511f01a4bf6b886fe34b6cce2513f ] The code prior to 311e305fdb4e ("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: 311e305fdb4e ("drm/vc4: hdmi: Implement a register layout abstraction") Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> Signed-off-by: Dom Cobley <popcornmix@xxxxxxxxx> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> Acked-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Tested-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210111142309.193441-4-maxime@xxxxxxxxxx (cherry picked from commit e9c9481f373eb7344f9e973eb28fc6e9d0f46485) Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/vc4/vc4_hdmi.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 1b2b5e3986ebd..f58098d2dc1d5 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -1313,13 +1313,20 @@ 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; @@ -1412,11 +1419,17 @@ 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) | -- 2.27.0