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[00/12] UBS: Cleanup in_interupt/in_irq/in_atomic() usage

Message ID 20201014145215.518912759@linutronix.de (mailing list archive)
Headers show
Series UBS: Cleanup in_interupt/in_irq/in_atomic() usage | expand

Message

Thomas Gleixner Oct. 14, 2020, 2:52 p.m. UTC 
Folks,

in the discussion about preempt count consistency accross kernel configurations:

  https://lore.kernel.org/r/20200914204209.256266093@linutronix.de/

Linus clearly requested that code in drivers and libraries which changes
behaviour based on execution context should either be split up so that
e.g. task context invocations and BH invocations have different interfaces
or if that's not possible the context information has to be provided by the
caller which knows in which context it is executing.

This includes conditional locking, allocation mode (GFP_*) decisions and
avoidance of code paths which might sleep.

In the long run, usage of 'preemptible, in_*irq etc.' should be banned from
driver code completely.

The usage of such constructs in USB is rather limited. Most of it is in
debug code and (misleading) comments. But of course there are also a few
few bugs including one unfixable.

With the following series applied, USB is clean.

Thanks,

	tglx
---
 atm/usbatm.c             |    2 
 core/buffer.c            |    6 +-
 core/hcd-pci.c           |    6 +-
 core/hcd.c               |   21 ++++----
 core/hub.c               |    3 -
 core/message.c           |   35 +++++++++-----
 core/usb.c               |    4 -
 gadget/udc/core.c        |    2 
 gadget/udc/dummy_hcd.c   |    5 +-
 gadget/udc/pxa27x_udc.c  |   19 ++++---
 host/ehci-fsl.c          |    9 +--
 host/ehci-pmcmsp.c       |   15 +++---
 host/isp1362.h           |    5 +-
 host/ohci-at91.c         |   11 +++-
 host/ohci-omap.c         |    7 +-
 host/ohci-pxa27x.c       |   11 ++--
 host/ohci-s3c2410.c      |   12 ++---
 host/xhci-mem.c          |    2 
 host/xhci.c              |    6 --
 misc/sisusbvga/Kconfig   |    2 
 serial/digi_acceleport.c |    7 +-
 serial/keyspan_pda.c     |  112 ++++++++++++++++++++---------------------------
 usbip/usbip_common.c     |    5 --
 23 files changed, 156 insertions(+), 151 deletions(-)

Comments

Pavel Machek Oct. 23, 2020, 8:01 a.m. UTC | #1 
> The usage of such constructs in USB is rather limited. Most of it is in
> debug code and (misleading) comments. But of course there are also a few
> few bugs including one unfixable.

The "UBS" typo in the subject got me confused for a while.

Best regards,
									Pavel