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Commit 2a22a1ca authored by Pali Rohár's avatar Pali Rohár Committed by Greg Kroah-Hartman
Browse files

firmware: turris-mox-rwtm: fail probing when firmware does not support hwrng 



[ Upstream commit 2eab59cf0d2036a5a9e264f719b71c21ccf679c2 ]

When Marvell's rWTM firmware, which does not support the GET_RANDOM
command, is used, kernel prints an error message
  hwrng: no data available
every 10 seconds.

Fail probing of this driver if the rWTM firmware does not support the
GET_RANDOM command.

Fixes: 389711b3 ("firmware: Add Turris Mox rWTM firmware driver")
Signed-off-by: default avatarPali Rohár <pali@kernel.org>
Signed-off-by: default avatarMarek Behún <kabel@kernel.org>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarGregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent b7c1bafe

drivers/firmware/turris-mox-rwtm.c

+28 −0
Original line number Diff line number Diff line
@@ -247,6 +247,27 @@ static int mox_get_board_info(struct mox_rwtm *rwtm) 
	return 0;

}



static int check_get_random_support(struct mox_rwtm *rwtm)

{

	struct armada_37xx_rwtm_tx_msg msg;

	int ret;



	msg.command = MBOX_CMD_GET_RANDOM;

	msg.args[0] = 1;

	msg.args[1] = rwtm->buf_phys;

	msg.args[2] = 4;



	ret = mbox_send_message(rwtm->mbox, &msg);

	if (ret < 0)

		return ret;



	ret = wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2);

	if (ret < 0)

		return ret;



	return mox_get_status(MBOX_CMD_GET_RANDOM, rwtm->reply.retval);

}



static int mox_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)

{

	struct mox_rwtm *rwtm = (struct mox_rwtm *) rng->priv;
@@ -338,6 +359,13 @@ static int turris_mox_rwtm_probe(struct platform_device *pdev) 
	if (ret < 0)

		dev_warn(dev, "Cannot read board information: %i\n", ret);



	ret = check_get_random_support(rwtm);

	if (ret < 0) {

		dev_notice(dev,

			   "Firmware does not support the GET_RANDOM command\n");

		goto free_channel;

	}



	rwtm->hwrng.name = DRIVER_NAME "_hwrng";

	rwtm->hwrng.read = mox_hwrng_read;

	rwtm->hwrng.priv = (unsigned long) rwtm;