Hi Boris

On 5/17/21 9:41 AM, Boris Brezillon wrote:

On Fri, 7 May 2021 15:17:54 +0200
[off-list ref] wrote:

quoted

+/**
+ * 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

quoted

+{
+	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);
+

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel