Commit ce514dad authored by Paulo Miguel Almeida's avatar Paulo Miguel Almeida Committed by Greg Kroah-Hartman
Browse files

staging: pi433: enforce tx_cfg to be set before any message can be sent 



this driver relies on exposing a char device to userspace to tx
messages. Every message can be sent using different trasmitter settings
such so the tx_cfg must be written before sending any messages.
Failing to do so will cause the message to fail silently depending on
printk/dynamic_debug settings which makes it hard to troubleshoot.

This patch add a control variable that will get initialized once tx_cfg
is set for the fd used when interacting with the char device.

Signed-off-by: default avatarPaulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
Link: https://lore.kernel.org/r/20220114221643.GA7843@mail.google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 39ddef56

drivers/staging/pi433/pi433_if.c

+14 −2
Original line number Diff line number Diff line
@@ -108,6 +108,9 @@ struct pi433_device { 
struct pi433_instance {

	struct pi433_device	*device;

	struct pi433_tx_cfg	tx_cfg;



	/* control flags */

	bool			tx_cfg_initialized;

};



/*-------------------------------------------------------------------------*/
@@ -823,6 +826,16 @@ pi433_write(struct file *filp, const char __user *buf, 
	if (count > MAX_MSG_SIZE)

		return -EMSGSIZE;



	/*

	 * check if tx_cfg has been initialized otherwise we won't be able to

	 * config the RF trasmitter correctly due to invalid settings

	 */

	if (!instance->tx_cfg_initialized) {

		dev_notice_once(device->dev,

				"write: failed due to unconfigured tx_cfg (see PI433_IOC_WR_TX_CFG)");

		return -EINVAL;

	}



	/*

	 * write the following sequence into fifo:

	 * - tx_cfg
@@ -897,6 +910,7 @@ pi433_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
			return -EFAULT;

		mutex_lock(&device->tx_fifo_lock);

		memcpy(&instance->tx_cfg, &tx_cfg, sizeof(struct pi433_tx_cfg));

		instance->tx_cfg_initialized = true;

		mutex_unlock(&device->tx_fifo_lock);

		break;

	case PI433_IOC_RD_RX_CFG:
@@ -949,8 +963,6 @@ static int pi433_open(struct inode *inode, struct file *filp) 


	/* setup instance data*/

	instance->device = device;

	instance->tx_cfg.bit_rate = 4711;

	// TODO: fill instance->tx_cfg;



	/* instance data as context */

	filp->private_data = instance;