From: Patrice CHOTARD <patrice.chotard@foss.st.com>
To: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Mark Brown <broonie@kernel.org>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
<linux-mtd@lists.infradead.org>,
Alexandre Torgue <alexandre.torgue@foss.st.com>,
<linux-spi@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <christophe.kerello@foss.st.com>
Subject: Re: [PATCH v2 1/3] spi: spi-mem: add automatic poll status functions
Date: Mon, 17 May 2021 11:24:25 +0200 [thread overview]
Message-ID: <e70b13ba-7f65-7ff1-0517-94b39615dcdb@foss.st.com> (raw)
In-Reply-To: <20210517094140.53cb643a@collabora.com>
Hi Boris
On 5/17/21 9:41 AM, Boris Brezillon wrote:
> On Fri, 7 May 2021 15:17:54 +0200
> <patrice.chotard@foss.st.com> wrote:
>
>> +/**
>> + * spi_mem_poll_status() - Poll memory device status
>> + * @mem: SPI memory device
>> + * @op: the memory operation to execute
>> + * @mask: status bitmask to ckeck
>> + * @match: (status & mask) expected value
>> + * @timeout_ms: timeout in milliseconds
>> + *
>> + * This function send a polling status request to the controller driver
>> + *
>> + * Return: 0 in case of success, -ETIMEDOUT in case of error,
>> + * -EOPNOTSUPP if not supported.
>> + */
>> +int spi_mem_poll_status(struct spi_mem *mem,
>> + const struct spi_mem_op *op,
>> + u16 mask, u16 match, u16 timeout_ms)
>
> Maybe you should pass a delay_us too, to poll the status at the right
> rate in the SW-based case (can also be used by drivers if they need to
Ok, i will add a polling_rate_us parameter to poll_status() callback,
even if in STM32 driver case we will not use it, i agree it should be useful
depending of driver's implementation.
> configure the polling rate). You could also add an initial_delay_us to
> avoid polling the status too early: an erase operation will take longer
> than a write which will take longer than a read. No need to check the
> status just after issuing the command, especially if the polling is
> done in SW. Those 2 arguments should also be passed to the driver.
Regarding the addition of an initial_delay_us. We got two solution:
- use the same polling rate already used by read_poll_timeout() and
set read_poll_timeout()'s sleep_before_read parameter to true (in our case 20 us
will be used as initial delay and as polling rate).
- add an udelay(initial_delay_us) or even better usleep_range(initial_delay_us,
initial_delay_us + delta) before calling read_poll_timeout().
I imagine you prefer the second solution ?
By adding polling_rate_us and initial_delay_us parameters to
spi_mem_poll_status(), it implies to update all spinand_wait() calls for
different operations (reset, read page, write page, erase) with respective
initial_delay_us/polling_rate_us values for spi_mem_poll_status()'s parameters.
Can you provide adequate initial_delay_us and polling rate_us for each operation type ?.
Thanks
Patrice
>
>> +{
>> + struct spi_controller *ctlr = mem->spi->controller;
>> + unsigned long ms;
>> + int ret = -EOPNOTSUPP;
>> + int exec_op_ret;
>> + u16 *status;
>> +
>> + if (!spi_mem_supports_op(mem, op))
>> + return ret;
>> +
>> + if (ctlr->mem_ops && ctlr->mem_ops->poll_status) {
>> + ret = spi_mem_access_start(mem);
>> + if (ret)
>> + return ret;
>> +
>> + reinit_completion(&ctlr->xfer_completion);
>> +
>> + ret = ctlr->mem_ops->poll_status(mem, op, mask, match,
>> + timeout_ms);
>> +
>> + ms = wait_for_completion_timeout(&ctlr->xfer_completion,
>> + msecs_to_jiffies(timeout_ms));
>> +
>> + spi_mem_access_end(mem);
>> + if (!ms)
>> + return -ETIMEDOUT;
>> + } else {
>> + status = (u16 *)op->data.buf.in;
>> + ret = read_poll_timeout(spi_mem_exec_op, exec_op_ret,
>> + ((*status) & mask) == match, 20,
>> + timeout_ms * 1000, false, mem, op);
>> + if (exec_op_ret)
>> + return exec_op_ret;
>> + }
>> +
>> + return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(spi_mem_poll_status);
>> +
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next prev parent reply other threads:[~2021-05-17 9:29 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-07 13:17 [PATCH v2 0/3] MTD: spinand: Add spi_mem_poll_status() support patrice.chotard
2021-05-07 13:17 ` [PATCH v2 1/3] spi: spi-mem: add automatic poll status functions patrice.chotard
2021-05-08 7:55 ` Boris Brezillon
2021-05-10 8:46 ` Patrice CHOTARD
2021-05-10 9:22 ` Boris Brezillon
2021-05-17 7:29 ` Patrice CHOTARD
2021-05-17 7:41 ` Boris Brezillon
2021-05-17 9:24 ` Patrice CHOTARD [this message]
2021-05-17 11:25 ` Boris Brezillon
2021-05-17 11:59 ` Patrice CHOTARD
2021-05-17 12:24 ` Boris Brezillon
2021-05-17 12:04 ` Patrice CHOTARD
2021-05-07 13:17 ` [PATCH v2 2/3] mtd: spinand: use the spi-mem poll status APIs patrice.chotard
2021-05-07 13:17 ` [PATCH v2 3/3] spi: stm32-qspi: add automatic poll status feature patrice.chotard
2021-05-07 19:29 ` kernel test robot
2021-05-07 22:16 ` kernel test robot
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