From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>, vkoul@kernel.org
Cc: sanyog.r.kale@intel.com, yung-chuan.liao@linux.intel.com,
linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org
Subject: Re: [PATCH 5/6] soundwire: qcom: update register read/write routine
Date: Fri, 29 Jan 2021 13:33:30 -0600 [thread overview]
Message-ID: <5c69ed09-60be-2f3d-ed25-f6dbfcb9d62f@linux.intel.com> (raw)
In-Reply-To: <20210129173248.5941-6-srinivas.kandagatla@linaro.org>
On 1/29/21 11:32 AM, Srinivas Kandagatla wrote:
> In the existing code every soundwire register read and register write
> are kinda blocked. Each of these are using a special command id that
what does 'kinda blocked' mean?
> generates interrupt after it successfully finishes. This is really
> overhead, limiting and not really necessary unless we are doing
> something special.
>
> We can simply read/write the fifo that should also give exactly
> what we need! This will also allow to read/write registers in
> interrupt context, which was not possible with the special
> command approach.
This is really unclear, sorry.
> + if (id != SWR_BROADCAST_CMD_ID) {
> + if (id < 14)
> + id += 1;
> + else
> + id = 0;
that is really odd. if id=13 (group2) then id becomes 14 (master
address). A comment is really needed here.
> + if (cmd_id == SWR_BROADCAST_CMD_ID) {
> + /*
> + * sleep for 10ms for MSM soundwire variant to allow broadcast
> + * command to complete.
that's also super-odd. There is nothing in SoundWire that makes any
difference between a regular and a broadcast command. they all complete
in the same time (a frame).
> + */
> + ret = wait_for_completion_timeout(&swrm->broadcast, (2 * HZ/10));
is this 10ms really or dependent on CONFIG_HZ?
> + if (!ret)
> + ret = SDW_CMD_IGNORED;
> + else
> + ret = SDW_CMD_OK;
no CMD_FAILED support?
> +static int qcom_swrm_cmd_fifo_rd_cmd(struct qcom_swrm_ctrl *swrm,
> + u8 dev_addr, u16 reg_addr,
> + u32 len, u8 *rval)
> +{
> + u32 val;
> + u32 retry_attempt = 0;
> + u32 cmd_data;
> + int ret = SDW_CMD_OK;
> +
> + mutex_lock(&swrm->io_lock);
> + val = swrm_get_packed_reg_val(&swrm->rcmd_id, len, dev_addr, reg_addr);
> +
> + /* wait for FIFO RD to complete to avoid overflow */
> + usleep_range(100, 105);
> + swrm->reg_write(swrm, SWRM_CMD_FIFO_RD_CMD, val);
> + /* wait for FIFO RD CMD complete to avoid overflow */
> + usleep_range(250, 255);
> +
> +retry_read:
> +
> + swrm->reg_read(swrm, SWRM_CMD_FIFO_RD_FIFO_ADDR, &cmd_data);
> + rval[0] = cmd_data & 0xFF;
> +
> + if ((((cmd_data) & 0xF00) >> 8) != swrm->rcmd_id) {
> + if (retry_attempt < MAX_FIFO_RD_FAIL_RETRY) {
> + /* wait 500 us before retry on fifo read failure */
> + usleep_range(500, 505);
> + if (retry_attempt == (MAX_FIFO_RD_FAIL_RETRY - 1)) {
> + swrm->reg_write(swrm, SWRM_CMD_FIFO_CMD, 0x1);
> + swrm->reg_write(swrm, SWRM_CMD_FIFO_RD_CMD, val);
> + }
> + retry_attempt++;
> + goto retry_read;
> + } else {
> + dev_err(swrm->dev,
> + "failed to read fifo: reg: 0x%x, \
> + rcmd_id: 0x%x, dev_num: 0x%x, cmd_data: 0x%x\n",
> + reg_addr, swrm->rcmd_id,
> + dev_addr, cmd_data);
> + ret = SDW_CMD_IGNORED;
> + }
> }
the flow seems complicated with multiple tests and goto? Can this be
simplified?
next prev parent reply other threads:[~2021-01-29 20:19 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-29 17:32 [PATCH 0/6] soundwire: qcom: various improvements Srinivas Kandagatla
2021-01-29 17:32 ` [PATCH 1/6] soundwire: qcom: add support to missing transport params Srinivas Kandagatla
2021-01-29 19:20 ` Pierre-Louis Bossart
2021-02-01 15:50 ` Srinivas Kandagatla
2021-02-01 16:33 ` Pierre-Louis Bossart
2021-02-01 14:13 ` Vinod Koul
2021-02-01 15:50 ` Srinivas Kandagatla
2021-01-29 17:32 ` [PATCH 2/6] soundwire: qcom: extract version field Srinivas Kandagatla
2021-01-29 17:32 ` [PATCH 3/6] soundwire: qcom: set continue execution flag for ignored commands Srinivas Kandagatla
2021-01-29 19:21 ` Pierre-Louis Bossart
2021-02-01 14:16 ` Vinod Koul
2021-02-01 15:50 ` Srinivas Kandagatla
2021-02-02 4:46 ` Vinod Koul
2021-01-29 17:32 ` [PATCH 4/6] soundwire: qcom: start the clock during initialization Srinivas Kandagatla
2021-02-01 14:21 ` Vinod Koul
2021-02-01 15:50 ` Srinivas Kandagatla
2021-02-02 4:46 ` Vinod Koul
2021-01-29 17:32 ` [PATCH 5/6] soundwire: qcom: update register read/write routine Srinivas Kandagatla
2021-01-29 19:33 ` Pierre-Louis Bossart [this message]
2021-02-01 15:50 ` Srinivas Kandagatla
2021-02-01 16:42 ` Pierre-Louis Bossart
2021-02-02 10:19 ` Srinivas Kandagatla
2021-02-02 16:58 ` Pierre-Louis Bossart
2021-02-01 14:26 ` Vinod Koul
2021-02-01 15:50 ` Srinivas Kandagatla
2021-01-29 17:32 ` [PATCH 6/6] soundwire: qcom: add support to new interrupts Srinivas Kandagatla
2021-01-29 19:38 ` Pierre-Louis Bossart
2021-02-01 15:51 ` Srinivas Kandagatla
2021-02-01 14:31 ` Vinod Koul
2021-02-01 15:51 ` Srinivas Kandagatla
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