On Fri, Dec 04, 2015 at 09:35:07AM +0100, Enric Balletbo i Serra wrote: > +static int sp_wait_aux_op_finish(struct anx78xx *anx78xx) > +{ > + u8 errcnt; > + u8 val; > + struct device *dev = &anx78xx->client->dev; > + > + errcnt = 150; > + while (errcnt--) { > + sp_reg_read(anx78xx, TX_P0, SP_DP_AUX_CH_CTRL2_REG, &val); > + if (!(val & SP_AUX_EN)) > + break; > + usleep_range(2000, 4000); > + } > + > + if (!errcnt) { This is off by one. It should be: while (--errcnt) { ... } if (errcnt == 0) return -EWHATEVER; Or: while (errcnt--) { ... } if (errcnt == -1) return -EWHATEVER; Also "errcnt" is a bad name, it should be retry_cnt or something (or maybe it actually is counting errors?). Also -1 is never a correct error code, please change all the -1 returns to something better. > + /* Buffer size of AUX CH is 16 */ > + if (count > 16) > + return -1; Just make a define so that you don't need to add comments about why 16 is correct. if (count > SIZE_AUX_CH) return -EINVAL; > + errcnt = 10; > + while (errcnt--) { > + sp_reg_read(anx78xx, TX_P0, SP_DP_AUX_CH_CTRL2_REG, &val); > + if (!(val & SP_AUX_EN)) > + break; > + usleep_range(1000, 2000); > + } > + > + if (!errcnt) { > + dev_err(dev, > + "failed to read DP AUX Channel Control Register 2\n"); > + sp_reset_aux(anx78xx); > + return -1; > + } Off by one again. > + > + sp_reg_write(anx78xx, TX_P0, SP_AUX_ADDR_7_0_REG, SP_I2C_EXTRA_ADDR); > + sp_tx_aux_wr(anx78xx, offset); > + /* read 16 bytes (MOT = 1) */ > + sp_tx_aux_rd(anx78xx, 0xf0 | DP_AUX_I2C_MOT | DP_AUX_I2C_READ); > + > + for (i = 0; i < 16; i++) { > + errcnt = 10; > + while (errcnt--) { > + sp_reg_read(anx78xx, TX_P0, SP_BUF_DATA_COUNT_REG, > + &val); > + if (val & SP_BUF_DATA_COUNT_MASK) > + break; > + usleep_range(2000, 4000); > + } > + > + if (!errcnt) { > + dev_err(dev, > + "failed to read DP Buffer Data Count Register\n"); > + sp_reset_aux(anx78xx); > + return -1; > + } And here. > + errcnt = 10; > + while (errcnt--) { > + sp_reg_read(anx78xx, TX_P0, SP_DP_AUX_CH_CTRL2_REG, &val); > + if (!(val & SP_AUX_EN)) > + break; > + usleep_range(1000, 2000); > + } > + > + if (!errcnt) { > + dev_err(dev, > + "failed to read DP AUX Channel Control Register 2\n"); > + sp_reset_aux(anx78xx); > + return -1; > + } Here. > + > + return 0; > +} > + > +static int sp_edid_block_checksum(const u8 *raw_edid) > +{ > + int i; > + u8 csum = 0; > + > + for (i = 0; i < EDID_LENGTH; i++) > + csum += raw_edid[i]; > + > + return csum; > +} > + > +static int sp_tx_edid_read(struct anx78xx *anx78xx) > +{ > + struct device *dev = &anx78xx->client->dev; > + u8 val, last_block, offset = 0; > + u8 buf[16]; > + int i, j, count; > + > + sp_tx_edid_read_initial(anx78xx); > + sp_reg_write(anx78xx, TX_P0, SP_DP_AUX_CH_CTRL1_REG, 0x04); > + sp_reg_set_bits(anx78xx, TX_P0, SP_DP_AUX_CH_CTRL2_REG, > + SP_AUX_EN | SP_ADDR_ONLY); > + > + if (sp_wait_aux_op_finish(anx78xx)) > + return -1; > + > + sp_addronly_set(anx78xx, false); > + > + /* Read the number of blocks */ > + sp_tx_aux_wr(anx78xx, 0x7e); > + sp_tx_aux_rd(anx78xx, DP_AUX_I2C_READ); > + sp_reg_read(anx78xx, TX_P0, SP_DP_BUF_DATA0_REG, &last_block); > + dev_dbg(dev, "last EDID block is %d\n", last_block); > + > + /* FIXME: Why not just cap to 3 if the reported value is >3 */ > + if (last_block > 3) > + last_block = 1; > + > + /* for every block */ > + for (count = 0; count <= last_block; count++) { > + switch (count) { > + case 0: > + case 1: > + for (i = 0; i < 8; i++) { > + offset = (i + count * 8) * 16; > + if (sp_edid_read(anx78xx, offset, buf)) > + return -1; > + for (j = 0; j < 16; j++) > + sp.edid_blocks[offset + j] = buf[j]; > + } > + break; > + case 2: > + case 3: > + offset = (count == 2) ? 0x00 : 0x80; > + for (j = 0; j < 8; j++) { > + if (sp_seg_edid_read(anx78xx, count / 2, > + offset)) > + return -1; > + offset = offset + 0x10; > + } > + break; > + default: > + break; Is there something which complains if you leave out the default case statement? It's not reachable. > + } > + } > + > + sp_reset_aux(anx78xx); > + > + if (!drm_edid_block_valid(sp.edid_blocks, 0, true, NULL)) { > + dev_err(dev, "EDID block is invalid\n"); > + return -1; > + } > + > + sp_dp_read_bytes_from_dpcd(anx78xx, DP_TEST_REQUEST, 1, &val); > + if (val & DP_TEST_LINK_EDID_READ) { > + dev_dbg(dev, "EDID test requested\n"); > + val = sp_edid_block_checksum(sp.edid_blocks); > + dev_dbg(dev, "EDID checksum is %d\n", val); > + sp_dp_write_bytes_to_dpcd(anx78xx, DP_TEST_EDID_CHECKSUM, 1, > + &val); > + sp.tx_test_edid = true; > + val = DP_TEST_EDID_CHECKSUM_WRITE; > + sp_dp_write_bytes_to_dpcd(anx78xx, DP_TEST_RESPONSE, 1, &val); > + } > + > + return 0; > +} > + > +static bool sp_check_with_pre_edid(struct anx78xx *anx78xx) > +{ > + struct device *dev = &anx78xx->client->dev; > + u8 i; > + u8 buf[16]; > + bool ret = false; > + > + sp_tx_edid_read_initial(anx78xx); > + sp_reg_write(anx78xx, TX_P0, SP_DP_AUX_CH_CTRL1_REG, 0x04); > + sp_reg_set_bits(anx78xx, TX_P0, SP_DP_AUX_CH_CTRL2_REG, 0x03); > + > + if (sp_wait_aux_op_finish(anx78xx)) > + goto return_point; > + > + sp_addronly_set(anx78xx, false); > + > + if (sp_edid_read(anx78xx, 0x70, buf)) > + goto return_point; > + > + for (i = 0; i < 16; i++) { > + if (sp.edid_blocks[0x70 + i] != buf[i]) { > + dev_dbg(dev, "%s\n", > + "different checksum and blocks num\n"); > + goto return_point; > + } > + } Can you just say: if (memcmp(&sp.edid_blocks[0x70], buf, 16) != 0) { dev_dbg(dev, "different checksum and blocks num\n"); goto return_point; } > + > + if (sp_edid_read(anx78xx, 0x08, buf)) > + goto return_point; > + > + for (i = 0; i < 16; i++) { > + if (sp.edid_blocks[i + 8] != buf[i]) { > + dev_dbg(dev, "different edid information\n"); > + goto return_point; > + } > + } > + > + ret = true; > +return_point: > + sp_reset_aux(anx78xx); > + > + return ret; > +} > + [ snip ] > +static bool sp_config_video_output(struct anx78xx *anx78xx) > +{ > + struct device *dev = &anx78xx->client->dev; > + u8 val; > + > + switch (sp.tx_vo_state) { > + default: > + case VO_WAIT_VIDEO_STABLE: > + sp_reg_read(anx78xx, RX_P0, SP_SYSTEM_STATUS_REG, &val); > + if ((val & SP_TMDS_DE_DET) && (val & SP_TMDS_CLOCK_DET)) { > + if (sp_tx_bw_lc_sel(anx78xx)) > + return false; > + sp_enable_video_input(anx78xx, false); > + sp_hdmi_new_avi_int(anx78xx); > + sp_reg_read(anx78xx, RX_P0, > + SP_PACKET_RECEIVING_STATUS_REG, &val); > + if (val & SP_VSI_RCVD) > + sp_hdmi_new_vsi_int(anx78xx); > + sp_enable_video_input(anx78xx, true); > + sp.tx_vo_state = VO_WAIT_TX_VIDEO_STABLE; > + } else { > + dev_dbg(dev, "HDMI input video not stable!\n"); > + break; > + } > + /* fallthrough */ > + case VO_WAIT_TX_VIDEO_STABLE: > + /* > + * The flag is write clear and can be latched from last > + * status. So the first read and write is to clear the > + * previous status. > + */ > + sp_reg_read(anx78xx, TX_P0, SP_DP_SYSTEM_CTRL_BASE + 2, &val); > + sp_reg_write(anx78xx, TX_P0, SP_DP_SYSTEM_CTRL_BASE + 2, val); > + > + sp_reg_read(anx78xx, TX_P0, SP_DP_SYSTEM_CTRL_BASE + 2, &val); > + if (val & SP_CHA_STA) { > + dev_dbg(dev, "stream clock not stable!\n"); > + break; > + } else { No need for the else statement. Pull it in one indent level. > + /* > + * The flag is write clear and can be latched from > + * last status. So the first read and write is to > + * clear the previous status. > + */ > + sp_reg_read(anx78xx, TX_P0, > + SP_DP_SYSTEM_CTRL_BASE + 3, > + &val); > + sp_reg_write(anx78xx, TX_P0, > + SP_DP_SYSTEM_CTRL_BASE + 3, > + val); > + > + sp_reg_read(anx78xx, TX_P0, > + SP_DP_SYSTEM_CTRL_BASE + 3, > + &val); > + if (val & SP_STRM_VALID) { > + if (sp.tx_test_lt) > + sp.tx_test_lt = false; > + sp.tx_vo_state = VO_FINISH; > + } else { > + dev_err(dev, "video stream not valid!\n"); > + break; > + } > + } > + /* fallthrough */ > + case VO_FINISH: > + sp_block_power_ctrl(anx78xx, SP_TX_PWR_AUDIO, false); > + sp_hdmi_mute_video(anx78xx, false); > + sp_video_mute(anx78xx, false); > + sp_show_information(anx78xx); > + return true; > + } > + > + return false; > +} > + [ snip ] > +static void sp_config_audio(struct anx78xx *anx78xx) > +{ > + int i; > + u8 val; > + > + sp_block_power_ctrl(anx78xx, SP_TX_PWR_AUDIO, true); > + > + sp_reg_read(anx78xx, TX_P0, SP_DP_MAIN_LINK_BW_SET_REG, &val); > + if (val & SP_INITIAL_SLIM_M_AUD_SEL) > + if (sp_calculate_audio_m_value(anx78xx)) > + return; Combine these: if ((val & SP_INITIAL_SLIM_M_AUD_SEL) && sp_calculate_audio_m_value(anx78xx)) return; > + > + sp_reg_clear_bits(anx78xx, TX_P1, SP_AUD_INTERFACE_CTRL0_REG, > + SP_AUD_INTERFACE_DISABLE); > + > + sp_reg_set_bits(anx78xx, TX_P1, SP_AUD_INTERFACE_CTRL2_REG, > + SP_M_AUD_ADJUST_ST); > + > + sp_reg_read(anx78xx, RX_P0, SP_HDMI_STATUS_REG, &val); > + if (val & SP_HDMI_AUD_LAYOUT) > + sp_reg_set_bits(anx78xx, TX_P2, SP_AUD_CH_STATUS_BASE + 5, > + SP_I2S_CH_NUM_8 | SP_AUDIO_LAYOUT); > + else > + sp_reg_clear_bits(anx78xx, TX_P2, SP_AUD_CH_STATUS_BASE + 5, > + SP_I2S_CHANNEL_NUM_MASK | SP_AUDIO_LAYOUT); > + > + /* transfer audio channel status from HDMI Rx to Slimport Tx */ > + for (i = 1; i <= SP_AUD_CH_STATUS_REG_NUM; i++) { > + sp_reg_read(anx78xx, RX_P0, SP_AUD_SPDIF_CH_STATUS_BASE + i, > + &val); > + sp_reg_write(anx78xx, TX_P2, SP_AUD_CH_STATUS_BASE + i, > + val); > + } Either this loop is off by one or the loop in sp_hdmi_audio_samplechg_int() is off by one. Also just call that function instead of re-implimenting it here. > + > + /* enable audio */ > + sp_enable_audio_output(anx78xx, true); > +} > + > +static bool sp_config_audio_output(struct anx78xx *anx78xx) > +{ > + u8 val; > + > + switch (sp.tx_ao_state) { > + default: > + case AO_INIT: > + case AO_CTS_RCV_INT: > + case AO_AUDIO_RCV_INT: > + sp_reg_read(anx78xx, RX_P0, SP_HDMI_STATUS_REG, &val); > + if (!val & SP_HDMI_MODE) { This is a precendence error. It should be: if (!(val & SP_HDMI_MODE)) { > + sp.tx_ao_state = AO_INIT; > + return true; > + } > + break; regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html