From 99f541524c8cd7b54a4f64a1c225de940e950833 Mon Sep 17 00:00:00 2001 From: Sean Paul Date: Thu, 1 Nov 2012 02:13:00 +0000 Subject: [PATCH] video: exynos_dp: Improve EDID error handling EDID error handling has 2 problems: - It doesn't fail as early as it can - The retry counts for i2c and aux transactions are huge This patch fails if the initial i2c transaction fails, and reduces the aux and i2c retry counts down to 3. [jg1.han@samsung.com: reduced the retry count of exynos_dp_read_byte_from_dpcd()] Signed-off-by: Sean Paul Signed-off-by: Jingoo Han --- drivers/video/exynos/exynos_dp_core.c | 13 ++++++++----- drivers/video/exynos/exynos_dp_reg.c | 14 ++++++-------- 2 files changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c index d60f8da720d1..a4c1dec763bd 100644 --- a/drivers/video/exynos/exynos_dp_core.c +++ b/drivers/video/exynos/exynos_dp_core.c @@ -91,9 +91,11 @@ static int exynos_dp_read_edid(struct exynos_dp_device *dp) */ /* Read Extension Flag, Number of 128-byte EDID extension blocks */ - exynos_dp_read_byte_from_i2c(dp, I2C_EDID_DEVICE_ADDR, + retval = exynos_dp_read_byte_from_i2c(dp, I2C_EDID_DEVICE_ADDR, EDID_EXTENSION_FLAG, &extend_block); + if (retval) + return retval; if (extend_block > 0) { dev_dbg(dp->dev, "EDID data includes a single extension!\n"); @@ -182,14 +184,15 @@ static int exynos_dp_handle_edid(struct exynos_dp_device *dp) int retval; /* Read DPCD DPCD_ADDR_DPCD_REV~RECEIVE_PORT1_CAP_1 */ - exynos_dp_read_bytes_from_dpcd(dp, - DPCD_ADDR_DPCD_REV, - 12, buf); + retval = exynos_dp_read_bytes_from_dpcd(dp, DPCD_ADDR_DPCD_REV, + 12, buf); + if (retval) + return retval; /* Read EDID */ for (i = 0; i < 3; i++) { retval = exynos_dp_read_edid(dp); - if (retval == 0) + if (!retval) break; } diff --git a/drivers/video/exynos/exynos_dp_reg.c b/drivers/video/exynos/exynos_dp_reg.c index 3f5ca8a0d5ea..fc19ef651565 100644 --- a/drivers/video/exynos/exynos_dp_reg.c +++ b/drivers/video/exynos/exynos_dp_reg.c @@ -491,7 +491,7 @@ int exynos_dp_read_byte_from_dpcd(struct exynos_dp_device *dp, int i; int retval; - for (i = 0; i < 10; i++) { + for (i = 0; i < 3; i++) { /* Clear AUX CH data buffer */ reg = BUF_CLR; writel(reg, dp->reg_base + EXYNOS_DP_BUFFER_DATA_CTL); @@ -552,7 +552,7 @@ int exynos_dp_write_bytes_to_dpcd(struct exynos_dp_device *dp, else cur_data_count = count - start_offset; - for (i = 0; i < 10; i++) { + for (i = 0; i < 3; i++) { /* Select DPCD device address */ reg = AUX_ADDR_7_0(reg_addr + start_offset); writel(reg, dp->reg_base + EXYNOS_DP_AUX_ADDR_7_0); @@ -617,7 +617,7 @@ int exynos_dp_read_bytes_from_dpcd(struct exynos_dp_device *dp, cur_data_count = count - start_offset; /* AUX CH Request Transaction process */ - for (i = 0; i < 10; i++) { + for (i = 0; i < 3; i++) { /* Select DPCD device address */ reg = AUX_ADDR_7_0(reg_addr + start_offset); writel(reg, dp->reg_base + EXYNOS_DP_AUX_ADDR_7_0); @@ -700,17 +700,15 @@ int exynos_dp_read_byte_from_i2c(struct exynos_dp_device *dp, int i; int retval; - for (i = 0; i < 10; i++) { + for (i = 0; i < 3; i++) { /* Clear AUX CH data buffer */ reg = BUF_CLR; writel(reg, dp->reg_base + EXYNOS_DP_BUFFER_DATA_CTL); /* Select EDID device */ retval = exynos_dp_select_i2c_device(dp, device_addr, reg_addr); - if (retval != 0) { - dev_err(dp->dev, "Select EDID device fail!\n"); + if (retval != 0) continue; - } /* * Set I2C transaction and read data @@ -750,7 +748,7 @@ int exynos_dp_read_bytes_from_i2c(struct exynos_dp_device *dp, int retval = 0; for (i = 0; i < count; i += 16) { - for (j = 0; j < 100; j++) { + for (j = 0; j < 3; j++) { /* Clear AUX CH data buffer */ reg = BUF_CLR; writel(reg, dp->reg_base + EXYNOS_DP_BUFFER_DATA_CTL);