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From: Philipp Hortmann <philipp.g.hortmann@gmail.com>
To: kernelnewbies@kernelnewbies.org
Subject: spin_lock_irqsave first used and then unused
Date: Sun, 30 Apr 2023 10:31:09 +0200	[thread overview]
Message-ID: <6a40d39a-c850-f330-eded-2f55127359b3@gmail.com> (raw)

Hi,

here a piece of code from driver rtl8192e:

	while (true) {
		spin_lock_irqsave(&priv->rf_ps_lock, flag);
		if (priv->rf_change_in_progress) {
			spin_unlock_irqrestore(&priv->rf_ps_lock, flag);

			while (priv->rf_change_in_progress) {
				rf_wait_counter++;
				mdelay(1);

				if (rf_wait_counter > 100) {
					netdev_warn(dev,
						    "%s(): Timeout waiting for RF change.\n",
						    __func__);
					return false;
				}
			}
		} else {
			priv->rf_change_in_progress = true;
			spin_unlock_irqrestore(&priv->rf_ps_lock, flag);
			break;
		}
	}

For me something is wrong here. First the access of 
priv->rf_change_in_progress is protected by a spin lock and then in the 
while loop it is unprotected. Is this correct? For me it is required to 
protected it always or protected it never.

Thanks for your support.

Bye Philipp

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             reply	other threads:[~2023-04-30  8:33 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-30  8:31 Philipp Hortmann [this message]
     [not found] ` <87o7n57b38.fsf@oltmanns.dev>
2023-04-30 15:57   ` spin_lock_irqsave first used and then unused Philipp Hortmann
2023-04-30 17:08     ` Torin Carey

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