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staging: wfx: drop async field from struct hif_cmd

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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: kbuild test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200907101521.66082-31-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jérôme Pouiller 2020-09-07 12:15:20 +02:00 committed by Greg Kroah-Hartman
parent c8fb880910
commit 3768c74b3a
3 changed files with 10 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/staging/wfx/hif_rx.c
View File

@ -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);
}
complete(&wdev->hif_cmd.done);
return status;
}

24
drivers/staging/wfx/hif_tx.c
View File

@ -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;
}

1
drivers/staging/wfx/hif_tx.h
View File

@ -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;