Commit 480f01ec authored by Yongxu Wang's avatar Yongxu Wang Committed by Fabio Baltieri
Browse files

drivers: firmware: scmi: disable interrupt communication in polling mode 



SCMI processor interrupts from agent are enabled by default during the
`setup_chan` initialization phase. This is suitable for interrupt-driven
communication, where the agent triggers an interrupt to notify the platform
after completing a message transaction.

However, when using the polling model, interrupts are not required and may
cause unintended behavior or performance issues in PM.
To ensure correct operation under polling mode, the interrupt should
be explicitly disabled after channel setup.

Signed-off-by: default avatarYongxu Wang <yongxu.wang@nxp.com>
parent d24b50e9

drivers/firmware/scmi/core.c

+38 −1
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <zephyr/drivers/firmware/scmi/transport.h>

#include <zephyr/logging/log.h>

#include <zephyr/device.h>

#include "mailbox.h"



LOG_MODULE_REGISTER(scmi_core);
@@ -87,15 +88,45 @@ static int scmi_core_setup_chan(const struct device *transport, 
	return 0;

}



static int scmi_interrupt_enable(struct scmi_channel *chan, bool enable)

{

	struct scmi_mbox_channel *mbox_chan;

	struct mbox_dt_spec *tx_reply;

	bool comp_int;



	mbox_chan = chan->data;

	comp_int = enable ? SCMI_SHMEM_CHAN_FLAG_IRQ_BIT : 0;



	if (mbox_chan->tx_reply.dev) {

		tx_reply = &mbox_chan->tx_reply;

	} else {

		tx_reply = &mbox_chan->tx;

	}



	/* re-set completion interrupt */

	scmi_shmem_update_flags(mbox_chan->shmem, SCMI_SHMEM_CHAN_FLAG_IRQ_BIT, comp_int);



	return mbox_set_enabled_dt(tx_reply, enable);

}



static int scmi_send_message_polling(struct scmi_protocol *proto,

					struct scmi_message *msg,

					struct scmi_message *reply)

{

	int ret;

	int status;



	/*

	 * SCMI communication interrupt is enabled by default during setup_chan

	 * to support interrupt-driven communication. When using polling mode

	 * it must be disabled to avoid unnecessary interrupts and

	 * ensure proper polling behavior.

	 */

	status = scmi_interrupt_enable(proto->tx, false);



	ret = scmi_transport_send_message(proto->transport, proto->tx, msg);

	if (ret < 0) {

		return ret;

		goto cleanup;

	}



	/* no kernel primitives, we're forced to poll here.
@@ -116,6 +147,12 @@ static int scmi_send_message_polling(struct scmi_protocol *proto, 
		return ret;

	}



cleanup:

	/* restore scmi interrupt enable status when disable it pass */

	if (status >= 0) {

		scmi_interrupt_enable(proto->tx, true);

	}



	return ret;

}

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