Hi Laurent,
On 20-12-2016 01:33, Laurent Pinchart wrote:
> Use the device version queried at runtime instead of the device type
> provided through platform data to handle the overflow workaround. This
> will make support of other SoCs integrating the same HDMI TX controller
> version easier.
>
> Among the supported platforms only i.MX6DL and i.MX6Q have been
> identified as needing the workaround. Disabling it on Rockchip RK3288
> (which integrates a v2.00a controller) didn't produce any error or
> artifact.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Reviewed-by: Jose Abreu <joabreu@xxxxxxxxxxxx>
Best regards,
Jose Miguel Abreu
> ---
> drivers/gpu/drm/bridge/dw-hdmi.c | 46 ++++++++++++++++++++++++++++------------
> 1 file changed, 33 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
> index 730a7558d4d4..f4faa14213e5 100644
> --- a/drivers/gpu/drm/bridge/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/dw-hdmi.c
> @@ -117,8 +117,10 @@ struct dw_hdmi {
> struct drm_connector connector;
> struct drm_bridge bridge;
>
> - struct platform_device *audio;
> enum dw_hdmi_devtype dev_type;
> + unsigned int version;
> +
> + struct platform_device *audio;
> struct device *dev;
> struct clk *isfr_clk;
> struct clk *iahb_clk;
> @@ -1323,19 +1325,38 @@ static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi)
> /* Workaround to clear the overflow condition */
> static void dw_hdmi_clear_overflow(struct dw_hdmi *hdmi)
> {
> - int count;
> + unsigned int count;
> + unsigned int i;
> u8 val;
>
> - /* TMDS software reset */
> - hdmi_writeb(hdmi, (u8)~HDMI_MC_SWRSTZ_TMDSSWRST_REQ, HDMI_MC_SWRSTZ);
> + /*
> + * Under some circumstances the Frame Composer arithmetic unit can miss
> + * an FC register write due to being busy processing the previous one.
> + * The issue can be worked around by issuing a TMDS software reset and
> + * then write one of the FC registers several times.
> + *
> + * The number of iterations matters and depends on the HDMI TX revision
> + * (and possibly on the platform). So far only i.MX6Q (v1.30a) and
> + * i.MX6DL (v1.31a) have been identified as needing the workaround, with
> + * 4 and 1 iterations respectively.
> + */
>
> - val = hdmi_readb(hdmi, HDMI_FC_INVIDCONF);
> - if (hdmi->dev_type == IMX6DL_HDMI) {
> - hdmi_writeb(hdmi, val, HDMI_FC_INVIDCONF);
> + switch (hdmi->version) {
> + case 0x130a:
> + count = 4;
> + break;
> + case 0x131a:
> + count = 1;
> + break;
> + default:
> return;
> }
>
> - for (count = 0; count < 4; count++)
> + /* TMDS software reset */
> + hdmi_writeb(hdmi, (u8)~HDMI_MC_SWRSTZ_TMDSSWRST_REQ, HDMI_MC_SWRSTZ);
> +
> + val = hdmi_readb(hdmi, HDMI_FC_INVIDCONF);
> + for (i = 0; i < count; i++)
> hdmi_writeb(hdmi, val, HDMI_FC_INVIDCONF);
> }
>
> @@ -1832,7 +1853,6 @@ __dw_hdmi_probe(struct platform_device *pdev,
> int irq;
> int ret;
> u32 val = 1;
> - u16 version;
> u8 prod_id0;
> u8 prod_id1;
> u8 config0;
> @@ -1917,21 +1937,21 @@ __dw_hdmi_probe(struct platform_device *pdev,
> }
>
> /* Product and revision IDs */
> - version = (hdmi_readb(hdmi, HDMI_DESIGN_ID) << 8)
> - | (hdmi_readb(hdmi, HDMI_REVISION_ID) << 0);
> + hdmi->version = (hdmi_readb(hdmi, HDMI_DESIGN_ID) << 8)
> + | (hdmi_readb(hdmi, HDMI_REVISION_ID) << 0);
> prod_id0 = hdmi_readb(hdmi, HDMI_PRODUCT_ID0);
> prod_id1 = hdmi_readb(hdmi, HDMI_PRODUCT_ID1);
>
> if (prod_id0 != HDMI_PRODUCT_ID0_HDMI_TX ||
> (prod_id1 & ~HDMI_PRODUCT_ID1_HDCP) != HDMI_PRODUCT_ID1_HDMI_TX) {
> dev_err(dev, "Unsupported HDMI controller (%04x:%02x:%02x)\n",
> - version, prod_id0, prod_id1);
> + hdmi->version, prod_id0, prod_id1);
> ret = -ENODEV;
> goto err_iahb;
> }
>
> dev_info(dev, "Detected HDMI TX controller v%x.%03x %s HDCP\n",
> - version >> 12, version & 0xfff,
> + hdmi->version >> 12, hdmi->version & 0xfff,
> prod_id1 & HDMI_PRODUCT_ID1_HDCP ? "with" : "without");
>
> initialize_hdmi_ih_mutes(hdmi);
