Re: [PATCH 4/6] drm/i915/dp: use the new drm helpers for dp aux

Rodrigo Vivi
2014-03-17T14:08:34Z

On Fri, Mar 14, 2014 at 11:51 AM, Jani Nikula <jani.nikula@intel.com> wrote:
> Functionality remains largely the same as before.
>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
> drivers/gpu/drm/i915/intel_dp.c | 257 +++++++++++++++++---------------------
> drivers/gpu/drm/i915/intel_drv.h | 1 +
> 2 files changed, 116 insertions(+), 142 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 22134edc03dd..24cbf4bd36c4 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -575,97 +575,77 @@ out:
> return ret;
> }
>
> -/* Write data to the aux channel in native mode */
> -static int
> -intel_dp_aux_native_write(struct intel_dp *intel_dp,
> - uint16_t address, uint8_t *send, int send_bytes)
> +#define HEADER_SIZE 4
> +static ssize_t
> +intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
> {
> + struct intel_dp *intel_dp = container_of(aux, struct intel_dp, aux);
> + uint8_t txbuf[20], rxbuf[20];
> + size_t txsize, rxsize;
> int ret;
> - uint8_t msg[20];
> - int msg_bytes;
> - uint8_t ack;
> - int retry;
>
> - if (WARN_ON(send_bytes > 16))
> - return -E2BIG;
> + txbuf[0] = msg->request << 4;
> + txbuf[1] = msg->address >> 8;
> + txbuf[2] = msg->address & 0xff;
> + txbuf[3] = msg->size - 1;
>
> - intel_dp_check_edp(intel_dp);
> - msg[0] = DP_AUX_NATIVE_WRITE << 4;
> - msg[1] = address >> 8;
> - msg[2] = address & 0xff;
> - msg[3] = send_bytes - 1;
> - memcpy(&msg[4], send, send_bytes);
> - msg_bytes = send_bytes + 4;
> - for (retry = 0; retry < 7; retry++) {

we were retrying 7 times always, but now we are now retrying only 3
times or even none.
Couldn't it trigger some new bug or regression?

> - ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes, &ack, 1);
> - if (ret < 0)
> - return ret;
> - ack >>= 4;
> - if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_ACK)
> - return send_bytes;
> - else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER)
> - usleep_range(400, 500);

we are also not checking this ack x defer (here nor in native_write)
replies anymore.
Don't we need it anymore? why?

> - else
> - return -EIO;
> - }
> + switch (msg->request & ~DP_AUX_I2C_MOT) {
> + case DP_AUX_NATIVE_WRITE:
> + case DP_AUX_I2C_WRITE:
> + txsize = HEADER_SIZE + msg->size;
> + rxsize = 1;
>
> - DRM_ERROR("too many retries, giving up\n");
> - return -EIO;
> -}
> + if (WARN_ON(txsize > 20))
> + return -E2BIG;
>
> -/* Write a single byte to the aux channel in native mode */
> -static int
> -intel_dp_aux_native_write_1(struct intel_dp *intel_dp,
> - uint16_t address, uint8_t byte)
> -{
> - return intel_dp_aux_native_write(intel_dp, address, &byte, 1);
> -}
> + memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size);
>
> -/* read bytes from a native aux channel */
> -static int
> -intel_dp_aux_native_read(struct intel_dp *intel_dp,
> - uint16_t address, uint8_t *recv, int recv_bytes)
> -{
> - uint8_t msg[4];
> - int msg_bytes;
> - uint8_t reply[20];
> - int reply_bytes;
> - uint8_t ack;
> - int ret;
> - int retry;
> + ret = intel_dp_aux_ch(intel_dp, txbuf, txsize, rxbuf, rxsize);
> + if (ret > 0) {
> + msg->reply = rxbuf[0] >> 4;
>
> - if (WARN_ON(recv_bytes > 19))
> - return -E2BIG;
> + /* Return payload size. */
> + ret = msg->size;
> + }
> + break;
>
> - intel_dp_check_edp(intel_dp);
> - msg[0] = DP_AUX_NATIVE_READ << 4;
> - msg[1] = address >> 8;
> - msg[2] = address & 0xff;
> - msg[3] = recv_bytes - 1;
> + case DP_AUX_NATIVE_READ:
> + case DP_AUX_I2C_READ:
> + txsize = HEADER_SIZE;
> + rxsize = msg->size + 1;
>
> - msg_bytes = 4;
> - reply_bytes = recv_bytes + 1;
> + if (WARN_ON(rxsize > 20))
> + return -E2BIG;
>
> - for (retry = 0; retry < 7; retry++) {
> - ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes,
> - reply, reply_bytes);
> - if (ret == 0)
> - return -EPROTO;
> - if (ret < 0)
> - return ret;
> - ack = reply[0] >> 4;
> - if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_ACK) {
> - memcpy(recv, reply + 1, ret - 1);
> - return ret - 1;
> + ret = intel_dp_aux_ch(intel_dp, txbuf, txsize, rxbuf, rxsize);
> + if (ret > 0) {
> + msg->reply = rxbuf[0] >> 4;
> + /*
> + * Assume happy day, and copy the data. The caller is
> + * expected to check msg->reply before touching it.
> + *
> + * Return payload size.
> + */
> + ret--;
> + memcpy(msg->buffer, rxbuf + 1, ret);
> }
> - else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER)
> - usleep_range(400, 500);
> - else
> - return -EIO;
> + break;
> +
> + default:
> + ret = -EINVAL;
> + break;
> }
>
> - DRM_ERROR("too many retries, giving up\n");
> - return -EIO;
> + return ret;
> +}
> +
> +static void
> +intel_dp_aux_init(struct intel_dp *intel_dp, struct intel_connector *connector)
> +{
> + struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +
> + intel_dp->aux.dev = dev->dev;
> + intel_dp->aux.transfer = intel_dp_aux_transfer;
> }
>
> static int
> @@ -1472,8 +1452,8 @@ void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode)
> return;
>
> if (mode != DRM_MODE_DPMS_ON) {
> - ret = intel_dp_aux_native_write_1(intel_dp, DP_SET_POWER,
> - DP_SET_POWER_D3);
> + ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
> + DP_SET_POWER_D3);
> if (ret != 1)
> DRM_DEBUG_DRIVER("failed to write sink power state\n");
> } else {
> @@ -1482,9 +1462,8 @@ void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode)
> * time to wake up.
> */
> for (i = 0; i < 3; i++) {
> - ret = intel_dp_aux_native_write_1(intel_dp,
> - DP_SET_POWER,
> - DP_SET_POWER_D0);
> + ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
> + DP_SET_POWER_D0);
> if (ret == 1)
> break;
> msleep(1);
> @@ -1708,13 +1687,11 @@ static void intel_edp_psr_enable_sink(struct intel_dp *intel_dp)
>
> /* Enable PSR in sink */
> if (intel_dp->psr_dpcd[1] & DP_PSR_NO_TRAIN_ON_EXIT)
> - intel_dp_aux_native_write_1(intel_dp, DP_PSR_EN_CFG,
> - DP_PSR_ENABLE &
> - ~DP_PSR_MAIN_LINK_ACTIVE);
> + drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG,
> + DP_PSR_ENABLE & ~DP_PSR_MAIN_LINK_ACTIVE);
> else
> - intel_dp_aux_native_write_1(intel_dp, DP_PSR_EN_CFG,
> - DP_PSR_ENABLE |
> - DP_PSR_MAIN_LINK_ACTIVE);
> + drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG,
> + DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE);
>
> /* Setup AUX registers */
> I915_WRITE(EDP_PSR_AUX_DATA1(dev), EDP_PSR_DPCD_COMMAND);
> @@ -2026,26 +2003,25 @@ static void vlv_dp_pre_pll_enable(struct intel_encoder *encoder)
> /*
> * Native read with retry for link status and receiver capability reads for
> * cases where the sink may still be asleep.
> + *
> + * Sinks are *supposed* to come up within 1ms from an off state, but we're also
> + * supposed to retry 3 times per the spec.
> */
> -static bool
> -intel_dp_aux_native_read_retry(struct intel_dp *intel_dp, uint16_t address,
> - uint8_t *recv, int recv_bytes)
> +static ssize_t
> +intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset,
> + void *buffer, size_t size)
> {
> - int ret, i;
> + ssize_t ret;
> + int i;
>
> - /*
> - * Sinks are *supposed* to come up within 1ms from an off state,
> - * but we're also supposed to retry 3 times per the spec.
> - */
> for (i = 0; i < 3; i++) {
> - ret = intel_dp_aux_native_read(intel_dp, address, recv,
> - recv_bytes);
> - if (ret == recv_bytes)
> - return true;
> + ret = drm_dp_dpcd_read(aux, offset, buffer, size);
> + if (ret == size)
> + return ret;
> msleep(1);
> }
>
> - return false;
> + return ret;
> }
>
> /*
> @@ -2055,10 +2031,10 @@ intel_dp_aux_native_read_retry(struct intel_dp *intel_dp, uint16_t address,
> static bool
> intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE])
> {
> - return intel_dp_aux_native_read_retry(intel_dp,
> - DP_LANE0_1_STATUS,
> - link_status,
> - DP_LINK_STATUS_SIZE);
> + return intel_dp_dpcd_read_wake(&intel_dp->aux,
> + DP_LANE0_1_STATUS,
> + link_status,
> + DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
> }
>
> /*
> @@ -2572,8 +2548,8 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,
> len = intel_dp->lane_count + 1;
> }
>
> - ret = intel_dp_aux_native_write(intel_dp, DP_TRAINING_PATTERN_SET,
> - buf, len);
> + ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_PATTERN_SET,
> + buf, len);
>
> return ret == len;
> }
> @@ -2602,9 +2578,8 @@ intel_dp_update_link_train(struct intel_dp *intel_dp, uint32_t *DP,
> I915_WRITE(intel_dp->output_reg, *DP);
> POSTING_READ(intel_dp->output_reg);
>
> - ret = intel_dp_aux_native_write(intel_dp, DP_TRAINING_LANE0_SET,
> - intel_dp->train_set,
> - intel_dp->lane_count);
> + ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_LANE0_SET,
> + intel_dp->train_set, intel_dp->lane_count);
>
> return ret == intel_dp->lane_count;
> }
> @@ -2660,11 +2635,11 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
> link_config[1] = intel_dp->lane_count;
> if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
> link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
> - intel_dp_aux_native_write(intel_dp, DP_LINK_BW_SET, link_config, 2);
> + drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_BW_SET, link_config, 2);
>
> link_config[0] = 0;
> link_config[1] = DP_SET_ANSI_8B10B;
> - intel_dp_aux_native_write(intel_dp, DP_DOWNSPREAD_CTRL, link_config, 2);
> + drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2);
>
> DP |= DP_PORT_EN;
>
> @@ -2907,8 +2882,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
>
> char dpcd_hex_dump[sizeof(intel_dp->dpcd) * 3];
>
> - if (intel_dp_aux_native_read_retry(intel_dp, 0x000, intel_dp->dpcd,
> - sizeof(intel_dp->dpcd)) == 0)
> + if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd,
> + sizeof(intel_dp->dpcd)) < 0)
> return false; /* aux transfer failed */
>
> hex_dump_to_buffer(intel_dp->dpcd, sizeof(intel_dp->dpcd),
> @@ -2921,9 +2896,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> /* Check if the panel supports PSR */
> memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
> if (is_edp(intel_dp)) {
> - intel_dp_aux_native_read_retry(intel_dp, DP_PSR_SUPPORT,
> - intel_dp->psr_dpcd,
> - sizeof(intel_dp->psr_dpcd));
> + intel_dp_dpcd_read_wake(&intel_dp->aux, DP_PSR_SUPPORT,
> + intel_dp->psr_dpcd,
> + sizeof(intel_dp->psr_dpcd));
> if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
> dev_priv->psr.sink_support = true;
> DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
> @@ -2945,9 +2920,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
> return true; /* no per-port downstream info */
>
> - if (intel_dp_aux_native_read_retry(intel_dp, DP_DOWNSTREAM_PORT_0,
> - intel_dp->downstream_ports,
> - DP_MAX_DOWNSTREAM_PORTS) == 0)
> + if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
> + intel_dp->downstream_ports,
> + DP_MAX_DOWNSTREAM_PORTS) < 0)
> return false; /* downstream port status fetch failed */
>
> return true;
> @@ -2963,11 +2938,11 @@ intel_dp_probe_oui(struct intel_dp *intel_dp)
>
> edp_panel_vdd_on(intel_dp);
>
> - if (intel_dp_aux_native_read_retry(intel_dp, DP_SINK_OUI, buf, 3))
> + if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
> DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
> buf[0], buf[1], buf[2]);
>
> - if (intel_dp_aux_native_read_retry(intel_dp, DP_BRANCH_OUI, buf, 3))
> + if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
> DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
> buf[0], buf[1], buf[2]);
>
> @@ -2982,46 +2957,40 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
> to_intel_crtc(intel_dig_port->base.base.crtc);
> u8 buf[1];
>
> - if (!intel_dp_aux_native_read(intel_dp, DP_TEST_SINK_MISC, buf, 1))
> + if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, buf) < 0);
> return -EAGAIN;
>
> if (!(buf[0] & DP_TEST_CRC_SUPPORTED))
> return -ENOTTY;
>
> - if (!intel_dp_aux_native_write_1(intel_dp, DP_TEST_SINK,
> - DP_TEST_SINK_START))
> + if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK,
> + DP_TEST_SINK_START) < 0)
> return -EAGAIN;
>
> /* Wait 2 vblanks to be sure we will have the correct CRC value */
> intel_wait_for_vblank(dev, intel_crtc->pipe);
> intel_wait_for_vblank(dev, intel_crtc->pipe);
>
> - if (!intel_dp_aux_native_read(intel_dp, DP_TEST_CRC_R_CR, crc, 6))
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0)
> return -EAGAIN;
>
> - intel_dp_aux_native_write_1(intel_dp, DP_TEST_SINK, 0);
> + drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, 0);
> return 0;
> }
>
> static bool
> intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
> {
> - int ret;
> -
> - ret = intel_dp_aux_native_read_retry(intel_dp,
> - DP_DEVICE_SERVICE_IRQ_VECTOR,
> - sink_irq_vector, 1);
> - if (!ret)
> - return false;
> -
> - return true;
> + return intel_dp_dpcd_read_wake(&intel_dp->aux,
> + DP_DEVICE_SERVICE_IRQ_VECTOR,
> + sink_irq_vector, 1) == 1;
> }
>
> static void
> intel_dp_handle_test_request(struct intel_dp *intel_dp)
> {
> /* NAK by default */
> - intel_dp_aux_native_write_1(intel_dp, DP_TEST_RESPONSE, DP_TEST_NAK);
> + drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_RESPONSE, DP_TEST_NAK);
> }
>
> /*
> @@ -3060,9 +3029,9 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
> intel_dp_get_sink_irq(intel_dp, &sink_irq_vector)) {
> /* Clear interrupt source */
> - intel_dp_aux_native_write_1(intel_dp,
> - DP_DEVICE_SERVICE_IRQ_VECTOR,
> - sink_irq_vector);
> + drm_dp_dpcd_writeb(&intel_dp->aux,
> + DP_DEVICE_SERVICE_IRQ_VECTOR,
> + sink_irq_vector);
>
> if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST)
> intel_dp_handle_test_request(intel_dp);
> @@ -3097,9 +3066,11 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
> intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
> uint8_t reg;
> - if (!intel_dp_aux_native_read_retry(intel_dp, DP_SINK_COUNT,
> - &reg, 1))
> +
> + if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
> + &reg, 1) < 0)
> return connector_status_unknown;
> +
> return DP_GET_SINK_COUNT(reg) ? connector_status_connected
> : connector_status_disconnected;
> }
> @@ -3925,6 +3896,8 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
> intel_dp_init_panel_power_sequencer(dev, intel_dp, &power_seq);
> }
>
> + intel_dp_aux_init(intel_dp, intel_connector);
> +
> error = intel_dp_i2c_init(intel_dp, intel_connector, name);
> WARN(error, "intel_dp_i2c_init failed with error %d for port %c\n",
> error, port_name(port));
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 2546cae0b4f0..561af4b013b1 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -491,6 +491,7 @@ struct intel_dp {
> uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
> struct i2c_adapter adapter;
> struct i2c_algo_dp_aux_data algo;
> + struct drm_dp_aux aux;
> uint8_t train_set[4];
> int panel_power_up_delay;
> int panel_power_down_delay;
> --
> 1.7.9.5
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Rodrigo Vivi
Blog: http://blog.vivi.eng.br