On Rockchip platform, sometimes driver would failed at reading EDID message, and it's caused by the AUX reply flag wouldn't received under the 100*10us wait time.
But after expand the wait time a little, the AUX reply flag would be set, so maybe the wait time is a little critical. Besides the analogix dp book haven't reminded the standard wait for looking AUX reply flag, so I thought it's okay to expand the wait time.
And the external wait time won't hurt Exynos DP too much, cause they wouldn't meet this problem, then driver would received the reply command very soon, so no more additional wait time would bring to Exynos platform.
Signed-off-by: Yakir Yang ykk@rock-chips.com --- Changes in v12: - Using another way to expand the AUX reply wait time (Jingoo)
Changes in v11: None 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 Changes in v2: None
drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c index cba3ffd..8687eea 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c @@ -471,7 +471,7 @@ int analogix_dp_start_aux_transaction(struct analogix_dp_device *dp) { int reg; int retval = 0; - int timeout_loop = 0; + unsigned long timeout;
/* Enable AUX CH operation */ reg = readl(dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_2); @@ -479,14 +479,12 @@ int analogix_dp_start_aux_transaction(struct analogix_dp_device *dp) writel(reg, dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_2);
/* Is AUX CH command reply received? */ - reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA); - while (!(reg & RPLY_RECEIV)) { - timeout_loop++; - if (DP_TIMEOUT_LOOP_COUNT < timeout_loop) { + timeout = jiffies + msecs_to_jiffies(5); + while ((readl(dp->reg_base + ANALOGIX_DP_INT_STA) & RPLY_RECEIV) == 0) { + if (time_after(jiffies, timeout)) { dev_err(dp->dev, "AUX CH command reply failed!\n"); return -ETIMEDOUT; } - reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA); usleep_range(10, 11); }