Commit 57aa557f authored by Jérôme Pouiller's avatar Jérôme Pouiller Committed by Greg Kroah-Hartman
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staging: wfx: introduce a way to poll IRQ 



It is possible to check if an IRQ is ending by polling the control
register. This function must used with care: if an IRQ fires while the
host reads control register, the IRQ can be lost. However, it could be
useful in some cases.

Signed-off-by: default avatarJérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200505123757.39506-8-Jerome.Pouiller@silabs.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a7efb625

drivers/staging/wfx/bh.c

+28 −0
Original line number Diff line number Diff line
@@ -307,6 +307,34 @@ void wfx_bh_request_tx(struct wfx_dev *wdev) 
	queue_work(system_highpri_wq, &wdev->hif.bh);

}



/*

 * If IRQ is not available, this function allow to manually poll the control

 * register and simulate an IRQ ahen an event happened.

 *

 * Note that the device has a bug: If an IRQ raise while host read control

 * register, the IRQ is lost. So, use this function carefully (only duing

 * device initialisation).

 */

void wfx_bh_poll_irq(struct wfx_dev *wdev)

{

	ktime_t now, start;

	u32 reg;



	start = ktime_get();

	for (;;) {

		control_reg_read(wdev, &reg);

		now = ktime_get();

		if (reg & 0xFFF)

			break;

		if (ktime_after(now, ktime_add_ms(start, 1000))) {

			dev_err(wdev->dev, "time out while polling control register\n");

			return;

		}

		udelay(200);

	}

	wfx_bh_request_rx(wdev);

}



void wfx_bh_register(struct wfx_dev *wdev)

{

	INIT_WORK(&wdev->hif.bh, bh_work);

drivers/staging/wfx/bh.h

+1 −0
Original line number Diff line number Diff line
@@ -28,5 +28,6 @@ void wfx_bh_register(struct wfx_dev *wdev); 
void wfx_bh_unregister(struct wfx_dev *wdev);

void wfx_bh_request_rx(struct wfx_dev *wdev);

void wfx_bh_request_tx(struct wfx_dev *wdev);

void wfx_bh_poll_irq(struct wfx_dev *wdev);



#endif /* WFX_BH_H */