Re: [BUG] radio-gemtek-pci.c: double mutex_lock

From: Jiri Kosina
Date: Thu Oct 08 2009 - 14:48:57 EST


On Thu, 8 Oct 2009, Alexander Strakh wrote:

> KERNEL_VERSION: 2.6.31
> DESCRIBE:
> In driver ./drivers/media/radio/radio-gemtek-pci.c
> mutex_lock is called first time in line 184, then in line 186
> gemtek_pci_setfrequency is called.
>
> 182 static void gemtek_pci_unmute(struct gemtek_pci *card)
> 183 {
> 184 mutex_lock(&card->lock);
> 185 if (card->mute) {
> 186 gemtek_pci_setfrequency(card, card->current_frequency);
> 187 card->mute = false;
> 188 }
> 189 mutex_unlock(&card->lock);190 }
>
> In gemtek_pci_setfrequency we call mutex_lock again in line 152
>
> 144 static void gemtek_pci_setfrequency(struct gemtek_pci *card, unsigned long
> frequency)
> 145 {
> 146 int i;
> 147 u32 value = frequency / 200 + 856;
> 148 u16 mask = 0x8000;
> 149 u8 last_byte;
> 150 u32 port = card->iobase;
> 151
> 152 mutex_lock(&card->lock);

Good catch. Adding Hans, who added the (incorrect) locking into
gemtek_pci_unmute(), to CC.

--
Jiri Kosina
SUSE Labs, Novell Inc.

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