drm/radeon/kms: improve aux error handling

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 151 insertions, 85 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index 695de9a38506..0f72f4d85c30 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -327,23 +327,23 @@ union aux_channel_transaction {
 };
 
 /* radeon aux chan functions */
-bool radeon_process_aux_ch(struct radeon_i2c_chan *chan, u8 *req_bytes,
-                           int num_bytes, u8 *read_byte,
-                           u8 read_buf_len, u8 delay)
+static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
+                                 u8 *send, int send_bytes,
+                                 u8 *recv, int recv_size,
+                                 u8 delay, u8 *ack)
 {
         struct drm_device *dev = chan->dev;
         struct radeon_device *rdev = dev->dev_private;
         union aux_channel_transaction args;
         int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
         unsigned char *base;
-        int retry_count = 0;
+        int recv_bytes;
 
         memset(&args, 0, sizeof(args));
 
         base = (unsigned char *)rdev->mode_info.atom_context->scratch;
 
-retry:
-        memcpy(base, req_bytes, num_bytes);
+        memcpy(base, send, send_bytes);
 
         args.v1.lpAuxRequest = 0;
         args.v1.lpDataOut = 16;
@@ -355,75 +355,103 @@ retry:
 
         atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
 
-        if (args.v1.ucReplyStatus && !args.v1.ucDataOutLen) {
-                if (args.v1.ucReplyStatus == 0x20 && retry_count++ < 10)
-                        goto retry;
-                DRM_DEBUG_KMS("failed to get auxch %02x%02x %02x %02x 0x%02x %02x after %d retries\n",
-                          req_bytes[1], req_bytes[0], req_bytes[2], req_bytes[3],
-                          chan->rec.i2c_id, args.v1.ucReplyStatus, retry_count);
-                return false;
+        *ack = args.v1.ucReplyStatus;
+
+        /* timeout */
+        if (args.v1.ucReplyStatus == 1) {
+                DRM_DEBUG_KMS("dp_aux_ch timeout\n");
+                return -ETIMEDOUT;
         }
 
-        if (args.v1.ucDataOutLen && read_byte && read_buf_len) {
-                if (read_buf_len < args.v1.ucDataOutLen) {
-                        DRM_ERROR("Buffer to small for return answer %d %d\n",
-                                  read_buf_len, args.v1.ucDataOutLen);
-                        return false;
-                }
-                {
-                        int len = min(read_buf_len, args.v1.ucDataOutLen);
-                        memcpy(read_byte, base + 16, len);
-                }
+        /* flags not zero */
+        if (args.v1.ucReplyStatus == 2) {
+                DRM_DEBUG_KMS("dp_aux_ch flags not zero\n");
+                return -EBUSY;
         }
-        return true;
+
+        /* error */
+        if (args.v1.ucReplyStatus == 3) {
+                DRM_DEBUG_KMS("dp_aux_ch error\n");
+                return -EIO;
+        }
+
+        recv_bytes = args.v1.ucDataOutLen;
+        if (recv_bytes > recv_size)
+                recv_bytes = recv_size;
+
+        if (recv && recv_size)
+                memcpy(recv, base + 16, recv_bytes);
+
+        return recv_bytes;
 }
 
-bool radeon_dp_aux_native_write(struct radeon_connector *radeon_connector, uint16_t address,
-                                uint8_t send_bytes, uint8_t *send)
+static int radeon_dp_aux_native_write(struct radeon_connector *radeon_connector,
+                                      u16 address, u8 *send, u8 send_bytes, u8 delay)
 {
         struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
+        int ret;
         u8 msg[20];
-        u8 msg_len, dp_msg_len;
-        bool ret;
+        int msg_bytes = send_bytes + 4;
+        u8 ack;
+
+        if (send_bytes > 16)
+                return -1;
 
-        dp_msg_len = 4;
         msg[0] = address;
         msg[1] = address >> 8;
         msg[2] = AUX_NATIVE_WRITE << 4;
-        dp_msg_len += send_bytes;
-        msg[3] = (dp_msg_len << 4) | (send_bytes - 1);
+        msg[3] = (msg_bytes << 4) | (send_bytes - 1);
+        memcpy(&msg[4], send, send_bytes);
 
-        if (send_bytes > 16)
-                return false;
+        while (1) {
+                ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
+                                            msg, msg_bytes, NULL, 0, delay, &ack);
+                if (ret < 0)
+                        return ret;
+                if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
+                        break;
+                else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
+                        udelay(400);
+                else
+                        return -EIO;
+        }
 
-        memcpy(&msg[4], send, send_bytes);
-        msg_len = 4 + send_bytes;
-        ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus, msg, msg_len, NULL, 0, 0);
-        return ret;
+        return send_bytes;
 }
 
-bool radeon_dp_aux_native_read(struct radeon_connector *radeon_connector, uint16_t address,
-                               uint8_t delay, uint8_t expected_bytes,
-                               uint8_t *read_p)
+static int radeon_dp_aux_native_read(struct radeon_connector *radeon_connector,
+                                     u16 address, u8 *recv, int recv_bytes, u8 delay)
 {
         struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
-        u8 msg[20];
-        u8 msg_len, dp_msg_len;
-        bool ret = false;
-        msg_len = 4;
-        dp_msg_len = 4;
+        u8 msg[4];
+        int msg_bytes = 4;
+        u8 ack;
+        int ret;
+
         msg[0] = address;
         msg[1] = address >> 8;
         msg[2] = AUX_NATIVE_READ << 4;
-        msg[3] = (dp_msg_len) << 4;
-        msg[3] |= expected_bytes - 1;
-
-        ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus, msg, msg_len, read_p, expected_bytes, delay);
-        return ret;
+        msg[3] = (msg_bytes << 4) | (recv_bytes - 1);
+
+        while (1) {
+                ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
+                                            msg, msg_bytes, recv, recv_bytes, delay, &ack);
+                if (ret == 0)
+                        return -EPROTO;
+                if (ret < 0)
+                        return ret;
+                if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
+                        return ret;
+                else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
+                        udelay(400);
+                else
+                        return -EIO;
+        }
 }
 
 /* radeon dp functions */
-static u8 radeon_dp_encoder_service(struct radeon_device *rdev, int action, int dp_clock,
+static u8 radeon_dp_encoder_service(struct radeon_device *rdev,
+                                    int action, int dp_clock,
                                     uint8_t ucconfig, uint8_t lane_num)
 {
         DP_ENCODER_SERVICE_PARAMETERS args;
@@ -456,8 +484,8 @@ bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
         u8 msg[25];
         int ret;
 
-        ret = radeon_dp_aux_native_read(radeon_connector, DP_DPCD_REV, 0, 8, msg);
-        if (ret) {
+        ret = radeon_dp_aux_native_read(radeon_connector, DP_DPCD_REV, msg, 8, 0);
+        if (ret > 0) {
                 memcpy(dig_connector->dpcd, msg, 8);
                 {
                         int i;
@@ -505,9 +533,9 @@ static bool atom_dp_get_link_status(struct radeon_connector *radeon_connector,
                                     u8 link_status[DP_LINK_STATUS_SIZE])
 {
         int ret;
-        ret = radeon_dp_aux_native_read(radeon_connector, DP_LANE0_1_STATUS, 100,
-                                        DP_LINK_STATUS_SIZE, link_status);
-        if (!ret) {
+        ret = radeon_dp_aux_native_read(radeon_connector, DP_LANE0_1_STATUS,
+                                        link_status, DP_LINK_STATUS_SIZE, 100);
+        if (ret <= 0) {
                 DRM_ERROR("displayport link status failed\n");
                 return false;
         }
@@ -535,22 +563,22 @@ static void dp_set_power(struct radeon_connector *radeon_connector, u8 power_sta
         struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
 
         if (dig_connector->dpcd[0] >= 0x11) {
-                radeon_dp_aux_native_write(radeon_connector, DP_SET_POWER, 1,
-                                           &power_state);
+                radeon_dp_aux_native_write(radeon_connector, DP_SET_POWER,
+                                           &power_state, 1, 0);
         }
 }
 
 static void dp_set_downspread(struct radeon_connector *radeon_connector, u8 downspread)
 {
-        radeon_dp_aux_native_write(radeon_connector, DP_DOWNSPREAD_CTRL, 1,
-                                   &downspread);
+        radeon_dp_aux_native_write(radeon_connector, DP_DOWNSPREAD_CTRL,
+                                   &downspread, 1, 0);
 }
 
 static void dp_set_link_bw_lanes(struct radeon_connector *radeon_connector,
                                  u8 link_configuration[DP_LINK_CONFIGURATION_SIZE])
 {
-        radeon_dp_aux_native_write(radeon_connector, DP_LINK_BW_SET, 2,
-                                   link_configuration);
+        radeon_dp_aux_native_write(radeon_connector, DP_LINK_BW_SET,
+                                   link_configuration, 2, 0);
 }
 
 static void dp_update_dpvs_emph(struct radeon_connector *radeon_connector,
@@ -566,14 +594,14 @@ static void dp_update_dpvs_emph(struct radeon_connector *radeon_connector,
                                                i, train_set[i]);
 
         radeon_dp_aux_native_write(radeon_connector, DP_TRAINING_LANE0_SET,
-                                   dig_connector->dp_lane_count, train_set);
+                                   train_set, dig_connector->dp_lane_count, 0);
 }
 
 static void dp_set_training(struct radeon_connector *radeon_connector,
                             u8 training)
 {
         radeon_dp_aux_native_write(radeon_connector, DP_TRAINING_PATTERN_SET,
-                                   1, &training);
+                                   &training, 1, 0);
 }
 
 void dp_link_train(struct drm_encoder *encoder,
@@ -756,16 +784,18 @@ void dp_link_train(struct drm_encoder *encoder,
 }
 
 int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
-                         uint8_t write_byte, uint8_t *read_byte)
+                         u8 write_byte, u8 *read_byte)
 {
         struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
         struct radeon_i2c_chan *auxch = (struct radeon_i2c_chan *)adapter;
-        int ret = 0;
-        uint16_t address = algo_data->address;
-        uint8_t msg[5];
-        uint8_t reply[2];
-        int msg_len, dp_msg_len;
-        int reply_bytes;
+        u16 address = algo_data->address;
+        u8 msg[5];
+        u8 reply[2];
+        unsigned retry;
+        int msg_bytes;
+        int reply_bytes = 1;
+        int ret;
+        u8 ack;
 
         /* Set up the command byte */
         if (mode & MODE_I2C_READ)
@@ -779,31 +809,67 @@ int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
         msg[0] = address;
         msg[1] = address >> 8;
 
-        reply_bytes = 1;
-
-        msg_len = 4;
-        dp_msg_len = 3;
         switch (mode) {
         case MODE_I2C_WRITE:
+                msg_bytes = 5;
+                msg[3] = msg_bytes << 4;
                 msg[4] = write_byte;
-                msg_len++;
-                dp_msg_len += 2;
                 break;
         case MODE_I2C_READ:
-                dp_msg_len += 1;
+                msg_bytes = 4;
+                msg[3] = msg_bytes << 4;
                 break;
         default:
+                msg_bytes = 4;
+                msg[3] = 3 << 4;
                 break;
         }
 
-        msg[3] = (dp_msg_len) << 4;
-        ret = radeon_process_aux_ch(auxch, msg, msg_len, reply, reply_bytes, 0);
+        for (retry = 0; retry < 4; retry++) {
+                ret = radeon_process_aux_ch(auxch,
+                                            msg, msg_bytes, reply, reply_bytes, 0, &ack);
+                if (ret < 0) {
+                        DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
+                        return ret;
+                }
+
+                switch (ack & AUX_NATIVE_REPLY_MASK) {
+                case AUX_NATIVE_REPLY_ACK:
+                        /* I2C-over-AUX Reply field is only valid
+                         * when paired with AUX ACK.
+                         */
+                        break;
+                case AUX_NATIVE_REPLY_NACK:
+                        DRM_DEBUG_KMS("aux_ch native nack\n");
+                        return -EREMOTEIO;
+                case AUX_NATIVE_REPLY_DEFER:
+                        DRM_DEBUG_KMS("aux_ch native defer\n");
+                        udelay(400);
+                        continue;
+                default:
+                        DRM_ERROR("aux_ch invalid native reply 0x%02x\n", ack);
+                        return -EREMOTEIO;
+                }
 
-        if (ret) {
-                if (read_byte)
-                        *read_byte = reply[0];
-                return reply_bytes;
+                switch (ack & AUX_I2C_REPLY_MASK) {
+                case AUX_I2C_REPLY_ACK:
+                        if (mode == MODE_I2C_READ)
+                                *read_byte = reply[0];
+                        return ret;
+                case AUX_I2C_REPLY_NACK:
+                        DRM_DEBUG_KMS("aux_i2c nack\n");
+                        return -EREMOTEIO;
+                case AUX_I2C_REPLY_DEFER:
+                        DRM_DEBUG_KMS("aux_i2c defer\n");
+                        udelay(400);
+                        break;
+                default:
+                        DRM_ERROR("aux_i2c invalid reply 0x%02x\n", ack);
+                        return -EREMOTEIO;
+                }
         }
+
+        DRM_ERROR("aux i2c too many retries, giving up\n");
         return -EREMOTEIO;
 }
 
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 7a3cfa09d45f..bb43573ff3cf 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -484,7 +484,7 @@ extern void atombios_dig_transmitter_setup(struct drm_encoder *encoder,
                                            int action, uint8_t lane_num,
                                            uint8_t lane_set);
 extern int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
-                                uint8_t write_byte, uint8_t *read_byte);
+                                u8 write_byte, u8 *read_byte);
 
 extern void radeon_i2c_init(struct radeon_device *rdev);
 extern void radeon_i2c_fini(struct radeon_device *rdev);