Commit 21243314 authored by Douglas Anderson's avatar Douglas Anderson Committed by Bjorn Andersson
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spi: spi-qcom-qspi: Avoid clock setting if not needed 



As per recent changes to the spi-qcom-qspi, now when we set the clock
we'll call into the interconnect framework and also call the OPP API.
Those are expensive operations.  Let's avoid calling them if possible.
This has a big impact on getting transfer rates back up to where they
were (or maybe slightly better) before those patches landed.

Fixes: cff80645 ("spi: spi-qcom-qspi: Add interconnect support")
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Acked-by: default avatarMark Brown <broonie@kernel.org>
Reviewed-by: default avatarRajendra Nayak <rnayak@codeaurora.org>
Tested-by: default avatarRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: default avatarMukesh Kumar Savaliya <msavaliy@codeaurora.org>
Reviewed-by: default avatarAkash Asthana <akashast@codeaurora.org>
Link: https://lore.kernel.org/r/20200709075113.v2.1.Ia7cb4f41ce93d37d0a764b47c8a453ce9e9c70ef@changeid


Signed-off-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
parent f79a158d

drivers/spi/spi-qcom-qspi.c

+31 −10
Original line number Diff line number Diff line
@@ -144,6 +144,7 @@ struct qcom_qspi { 
	struct icc_path *icc_path_cpu_to_qspi;

	struct opp_table *opp_table;

	bool has_opp_table;

	unsigned long last_speed;

	/* Lock to protect data accessed by IRQs */

	spinlock_t lock;

};
@@ -226,19 +227,13 @@ static void qcom_qspi_handle_err(struct spi_master *master, 
	spin_unlock_irqrestore(&ctrl->lock, flags);

}



static int qcom_qspi_transfer_one(struct spi_master *master,

				  struct spi_device *slv,

				  struct spi_transfer *xfer)

static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)

{

	struct qcom_qspi *ctrl = spi_master_get_devdata(master);

	int ret;

	unsigned long speed_hz;

	unsigned long flags;

	unsigned int avg_bw_cpu;



	speed_hz = slv->max_speed_hz;

	if (xfer->speed_hz)

		speed_hz = xfer->speed_hz;

	if (speed_hz == ctrl->last_speed)

		return 0;



	/* In regular operation (SBL_EN=1) core must be 4x transfer clock */

	ret = dev_pm_opp_set_rate(ctrl->dev, speed_hz * 4);
@@ -259,6 +254,28 @@ static int qcom_qspi_transfer_one(struct spi_master *master, 
		return ret;

	}



	ctrl->last_speed = speed_hz;



	return 0;

}



static int qcom_qspi_transfer_one(struct spi_master *master,

				  struct spi_device *slv,

				  struct spi_transfer *xfer)

{

	struct qcom_qspi *ctrl = spi_master_get_devdata(master);

	int ret;

	unsigned long speed_hz;

	unsigned long flags;



	speed_hz = slv->max_speed_hz;

	if (xfer->speed_hz)

		speed_hz = xfer->speed_hz;



	ret = qcom_qspi_set_speed(ctrl, speed_hz);

	if (ret)

		return ret;



	spin_lock_irqsave(&ctrl->lock, flags);



	/* We are half duplex, so either rx or tx will be set */
@@ -602,7 +619,11 @@ static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev) 
		return ret;

	}



	return clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);

	ret = clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);

	if (ret)

		return ret;



	return dev_pm_opp_set_rate(dev, ctrl->last_speed * 4);

}



static int __maybe_unused qcom_qspi_suspend(struct device *dev)

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