Commit 3768c74b authored by Jérôme Pouiller's avatar Jérôme Pouiller Committed by Greg Kroah-Hartman
Browse files

staging: wfx: drop async field from struct hif_cmd 

The parameter "async" in wfx_cmd_send() allows to send command without
waiting for the reply. In this case, the mutex hif_cmd.lock is released
asynchronously in the context of the receiver workqueue.

However, "kbuild test robot" complains about this architecture[1] since
it is not able to follow the lock duration of hif_cmd.lock (and indeed,
the state of the driver if the hardware wouldn't reply is not well
defined).

Besides, this feature is not really necessary. It is only used by
hif_shutdown(). This function hijack the 'async' flag to run a command
that won't answer.

So, this patch removes the 'async' flag and introduces a 'no_reply' flag.
Thus, the mutex hif_cmd.lock is only acquired/released from
hif_cmd_send(). Therefore:
  - hif_shutdown() does not have to touch the private data of the struct
    hif_cmd
  - Kbuild test robot should be happy
  - the resulting code is simpler

[1] https://lore.kernel.org/driverdev-devel/alpine.DEB.2.21.1910041317381.2992@hadrien/



Reported-by: default avatarkbuild test robot <lkp@intel.com>
Reported-by: default avatarJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: default avatarJérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200907101521.66082-31-Jerome.Pouiller@silabs.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c8fb8809

drivers/staging/wfx/hif_rx.c

+1 −6
Original line number Diff line number Diff line
@@ -47,12 +47,7 @@ static int hif_generic_confirm(struct wfx_dev *wdev, 
	}

	wdev->hif_cmd.ret = status;



	if (!wdev->hif_cmd.async) {

	complete(&wdev->hif_cmd.done);

	} else {

		wdev->hif_cmd.buf_send = NULL;

		mutex_unlock(&wdev->hif_cmd.lock);

	}

	return status;

}

drivers/staging/wfx/hif_tx.c

+9 −15
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ static void *wfx_alloc_hif(size_t body_len, struct hif_msg **hif) 
}



int wfx_cmd_send(struct wfx_dev *wdev, struct hif_msg *request,

		 void *reply, size_t reply_len, bool async)

		 void *reply, size_t reply_len, bool no_reply)

{

	const char *mib_name = "";

	const char *mib_sep = "";
@@ -55,8 +55,6 @@ int wfx_cmd_send(struct wfx_dev *wdev, struct hif_msg *request, 
	int vif = request->interface;

	int ret;



	WARN(wdev->hif_cmd.buf_recv && wdev->hif_cmd.async, "API usage error");



	// Do not wait for any reply if chip is frozen

	if (wdev->chip_frozen)

		return -ETIMEDOUT;
@@ -69,14 +67,18 @@ int wfx_cmd_send(struct wfx_dev *wdev, struct hif_msg *request, 
	wdev->hif_cmd.buf_send = request;

	wdev->hif_cmd.buf_recv = reply;

	wdev->hif_cmd.len_recv = reply_len;

	wdev->hif_cmd.async = async;

	complete(&wdev->hif_cmd.ready);



	wfx_bh_request_tx(wdev);



	// NOTE: no timeout is caught async is enabled

	if (async)

	if (no_reply) {

		// Chip won't reply. Give enough time to the wq to send the

		// buffer.

		msleep(100);

		wdev->hif_cmd.buf_send = NULL;

		mutex_unlock(&wdev->hif_cmd.lock);

		return 0;

	}



	if (wdev->poll_irq)

		wfx_bh_poll_irq(wdev);
@@ -118,29 +120,21 @@ int wfx_cmd_send(struct wfx_dev *wdev, struct hif_msg *request, 
}



// This function is special. After HIF_REQ_ID_SHUT_DOWN, chip won't reply to any

// request anymore. We need to slightly hack struct wfx_hif_cmd for that job. Be

// careful to only call this function during device unregister.

// request anymore. Obviously, only call this function during device unregister.

int hif_shutdown(struct wfx_dev *wdev)

{

	int ret;

	struct hif_msg *hif;



	if (wdev->chip_frozen)

		return 0;

	wfx_alloc_hif(0, &hif);

	if (!hif)

		return -ENOMEM;

	wfx_fill_header(hif, -1, HIF_REQ_ID_SHUT_DOWN, 0);

	ret = wfx_cmd_send(wdev, hif, NULL, 0, true);

	// After this command, chip won't reply. Be sure to give enough time to

	// bh to send buffer:

	msleep(100);

	wdev->hif_cmd.buf_send = NULL;

	if (wdev->pdata.gpio_wakeup)

		gpiod_set_value(wdev->pdata.gpio_wakeup, 0);

	else

		control_reg_write(wdev, 0);

	mutex_unlock(&wdev->hif_cmd.lock);

	kfree(hif);

	return ret;

}

drivers/staging/wfx/hif_tx.h

+0 −1
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ struct wfx_hif_cmd { 
	struct mutex      lock;

	struct completion ready;

	struct completion done;

	bool              async;

	struct hif_msg    *buf_send;

	void              *buf_recv;

	size_t            len_recv;