Messages in this thread | | | Subject | Re: [PATCH] pci: Fix a possible sleep-in-atomic bug in pci_set_power_state | From | Jia-Ju Bai <> | Date | Mon, 9 Oct 2017 16:32:33 +0800 |
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Oh, sorry, I will send the patches for each driver.
Thanks, Jia-Ju Bai
On 2017/10/9 16:17, Greg KH wrote: > On Mon, Oct 09, 2017 at 04:16:20PM +0800, Jia-Ju Bai wrote: >> The drivers vt6655 and gma500 call pci_set_power_state under a spinlock, which may sleep. >> The function call paths are: >> gma_power_begin (acquire the spinlock) (drivers/gpu/drm/gma500/power.c) >> gma_resume_pci >> pci_set_power_state >> __pci_start_power_transition (drivers/pci/pci.c) >> msleep --> may sleep >> >> gma_power_begin (acquire the spinlock) (drivers/gpu/drm/gma500/power.c) >> gma_resume_pci >> pci_enable_device >> pci_enable_device_flags (drivers/pci/pci.c) >> do_pci_enable_device >> pci_set_power_state >> __pci_start_power_transition >> msleep --> may sleep >> >> vt6655_suspend (acquire the spinlock) (drivers/staging/vt6655/device_main.c) >> pci_set_power_state >> __pci_start_power_transition (drivers/pci/pci.c) >> msleep --> may sleep >> >> To fix these bugs, msleep is replaced with mdelay in __pci_start_power_transition >> >> These bugs are found by my static analysis tool and my code review. > Wait, no, why not fix the callers to not have a spinlock. Those are the > only users of these calls that are doing so incorrectly, don't change > the PCI core for the fault of 2 broken drivers. > > thanks, > > greg k-h
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