mfd: cros_ec: spi: Make the cros_ec_spi timeout more reliable (c9a81d67) · Commits · 戴 / test

The cros_ec_spi transfer had two problems with its timeout code: 1. It looked at the timeout even in the case that it found valid data. 2. If the cros_ec_spi code got switched out for a while, it's possible it could get a timeout after a single loop. Let's be paranoid and make sure we do one last transfer after the timeout expires. Signed-off-by:

Doug Anderson <dianders@chromium.org> Reviewed-by:

Simon Glass <sjg@chromium.org> Tested-by:

Andrew Bresticker <abrestic@chromium.org> Tested-by:

Stephen Warren <swarren@nvidia.com> Signed-off-by:

Lee Jones <lee.jones@linaro.org>

drivers/mfd/cros_ec_spi.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -113,7 +113,9 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,

		/* Receive data until we see the header byte */
		deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
		do {
		while (true) {
		unsigned long start_jiffies = jiffies;

		memset(&trans, 0, sizeof(trans));
		trans.cs_change = 1;
		trans.rx_buf = ptr = ec_dev->din;
		@@ -134,12 +136,19 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
		break;
		}
		}
		if (ptr != end)
		break;

		if (time_after(jiffies, deadline)) {
		/*
		* Use the time at the start of the loop as a timeout. This
		* gives us one last shot at getting the transfer and is useful
		* in case we got context switched out for a while.
		*/
		if (time_after(start_jiffies, deadline)) {
		dev_warn(ec_dev->dev, "EC failed to respond in time\n");
		return -ETIMEDOUT;
		}
		} while (ptr == end);
		}

		/*
		* ptr now points to the header byte. Copy any valid data to the

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