HDMI_IH_I2CMPHY_STAT0 is a clear on write register, which indicates i2cm operation status(i2c transfer done or error), every hdmi phy register configuration must check this register to make sure the configuration has complete. But the indication bit should be cleared after check, otherwise the corresponding bit will hold on forever, this may give a wrong signal for next check.
Signed-off-by: Andy Yan andy.yan@rock-chips.com
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Changes in v13: None Changes in v12: None Changes in v11: - split form patch <dw_hdmi: add rk3288 support>
Changes in v10: None Changes in v9: None Changes in v8: None Changes in v7: None Changes in v6: None Changes in v5: None Changes in v4: None Changes in v3: None
drivers/gpu/drm/bridge/dw_hdmi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index b13e782..8aa5f61 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -668,11 +668,15 @@ static inline void hdmi_phy_test_dout(struct dw_hdmi *hdmi,
static bool hdmi_phy_wait_i2c_done(struct dw_hdmi *hdmi, int msec) { - while ((hdmi_readb(hdmi, HDMI_IH_I2CMPHY_STAT0) & 0x3) == 0) { + u32 val; + + while ((val = hdmi_readb(hdmi, HDMI_IH_I2CMPHY_STAT0) & 0x3) == 0) { if (msec-- == 0) return false; udelay(1000); } + hdmi_writeb(hdmi, val, HDMI_IH_I2CMPHY_STAT0); + return true; }