Re: [PATCH v6 3/4] soundwire: qcom: Add set_channel_map api support

[Dan Carpenter <dan.carpenter@linaro.org>]

On Thu, Feb 06, 2025 at 04:52:24PM +0530, Mohammad Rafi Shaik wrote:
> Added qcom_swrm_set_channel_map api to set the master channel mask for
> TX and RX paths based on the provided slots.
> 
> Added a new field ch_mask to the qcom_swrm_port_config structure.
> This field is used to store the master channel mask, which allows more
> flexible to configure channel mask in runtime for specific active
> soundwire ports.
> 
> Modified the qcom_swrm_port_enable function to configure master
> channel mask. If the ch_mask is set to SWR_INVALID_PARAM or is zero,
> the function will use the default channel mask.
> 
> Signed-off-by: Mohammad Rafi Shaik <quic_mohs@quicinc.com>
> Acked-by: Vinod Koul <vkoul@kernel.org>
> ---
>  drivers/soundwire/qcom.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> index 0f45e3404756..295a46dc2be7 100644
> --- a/drivers/soundwire/qcom.c
> +++ b/drivers/soundwire/qcom.c
> @@ -156,6 +156,7 @@ struct qcom_swrm_port_config {
>  	u8 word_length;
>  	u8 blk_group_count;
>  	u8 lane_control;
> +	u8 ch_mask;
>  };
>  
>  /*
> @@ -1048,9 +1049,13 @@ static int qcom_swrm_port_enable(struct sdw_bus *bus,
>  {
>  	u32 reg = SWRM_DP_PORT_CTRL_BANK(enable_ch->port_num, bank);
>  	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
> +	struct qcom_swrm_port_config *pcfg;
>  	u32 val;
>  
> +	pcfg = &ctrl->pconfig[enable_ch->port_num];
>  	ctrl->reg_read(ctrl, reg, &val);
> +	if (pcfg->ch_mask != SWR_INVALID_PARAM && pcfg->ch_mask != 0)
> +		enable_ch->ch_mask = pcfg->ch_mask;
>  
>  	if (enable_ch->enable)
>  		val |= (enable_ch->ch_mask << SWRM_DP_PORT_CTRL_EN_CHAN_SHFT);
> @@ -1270,6 +1275,26 @@ static void *qcom_swrm_get_sdw_stream(struct snd_soc_dai *dai, int direction)
>  	return ctrl->sruntime[dai->id];
>  }
>  
> +static int qcom_swrm_set_channel_map(struct snd_soc_dai *dai,
> +				     unsigned int tx_num, const unsigned int *tx_slot,
> +				     unsigned int rx_num, const unsigned int *rx_slot)
> +{
> +	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
> +	int i;
> +
> +	if (tx_slot) {
> +		for (i = 0; i < tx_num; i++)
> +			ctrl->pconfig[i].ch_mask = tx_slot[i];
> +	}
> +
> +	if (rx_slot) {
> +		for (i = 0; i < rx_num; i++)
> +			ctrl->pconfig[i].ch_mask = rx_slot[i];
> +	}
> +
> +	return 0;
> +}
> +

Could we fix or revert this patch?  It's called like this from
sdm845_dai_init():

sound/soc/qcom/sdm845.c
   247          /*
   248           * Codec SLIMBUS configuration
   249           * RX1, RX2, RX3, RX4, RX5, RX6, RX7, RX8, RX9, RX10, RX11, RX12, RX13
   250           * TX1, TX2, TX3, TX4, TX5, TX6, TX7, TX8, TX9, TX10, TX11, TX12, TX13
   251           * TX14, TX15, TX16
   252           */
   253          unsigned int rx_ch[SLIM_MAX_RX_PORTS] = {144, 145, 146, 147, 148, 149,
   254                                          150, 151, 152, 153, 154, 155, 156};
   255          unsigned int tx_ch[SLIM_MAX_TX_PORTS] = {128, 129, 130, 131, 132, 133,
   256                                              134, 135, 136, 137, 138, 139,
   257                                              140, 141, 142, 143};

[ snip ]

   304                  for_each_rtd_codec_dais(rtd, i, codec_dai) {
   305                          rval = snd_soc_dai_set_channel_map(codec_dai,
   306                                                            ARRAY_SIZE(tx_ch),
   307                                                            tx_ch,
   308                                                            ARRAY_SIZE(rx_ch),
   309                                                            rx_ch);
   310                          if (rval != 0 && rval != -ENOTSUPP)
   311                                  return rval;

There are 3 bugs:

Bug #1:
The zeroeth element of ctrl->pconfig[] is supposed to be unused.  We
start counting at 1.  However this code sets ctrl->pconfig[0].ch_mask = 128.

Bug #2:
There are SLIM_MAX_TX_PORTS (16) elements in tx_ch[] array but only
QCOM_SDW_MAX_PORTS + 1 (15) in the ctrl->pconfig[] array so it corrupts
memory like Yongqin Liu pointed out.

Bug 3:
Like Jie Gan pointed out, it erases all the tx information with the rx
information.

regards,
dan carpenter