Hi Dom & Maxime
On Thu, 10 Dec 2020 at 13:46, Maxime Ripard <maxime@xxxxxxxxxx> wrote:
>
> From: Dom Cobley <popcornmix@xxxxxxxxx>
>
> 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")
> Signed-off-by: Dom Cobley <popcornmix@xxxxxxxxx>
> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> ---
> 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 3df1747dd917..28b78ea885ea 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -1434,13 +1434,20 @@ 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;
> @@ -1533,11 +1540,17 @@ 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) |
> --
> 2.28.0
>
