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Message-ID: <20151207080956.GB18797@mwanda>
Date: Mon, 7 Dec 2015 11:09:56 +0300
From: Dan Carpenter <dan.carpenter@...cle.com>
To: Enric Balletbo i Serra <eballetbo@...il.com>
Cc: devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
dri-devel@...ts.freedesktop.org, devel@...verdev.osuosl.org,
treding@...dia.com, mark.rutland@....com, drinkcat@...omium.org,
laurent.pinchart@...asonboard.com, pawel.moll@....com,
ijc+devicetree@...lion.org.uk, airlied@...ux.ie,
gregkh@...uxfoundation.org, emil.l.velikov@...il.com,
cawa.cheng@...iatek.com, djkurtz@...omium.org,
jb.tsai@...iatek.com, sjoerd.simons@...labora.co.uk,
robh+dt@...nel.org, span@...logixsemi.com, galak@...eaurora.org,
javier@...hile0.org, eddie.huang@...iatek.com,
cjiao@...logixsemi.com, nathan.chung@...iatek.com
Subject: Re: [PATCHv6 5/5] drm: bridge: anx78xx: Add anx78xx driver support
by analogix.
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
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