Messages in this thread | | | Date | Thu, 24 Jan 2008 11:11:38 -0500 | From | Jarod Wilson <> | Subject | Re: [PATCH 4/4] firewire: fw-core: react on bus resets while the config ROM is being fetched |
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Stefan Richter wrote: > read_rom() obtained a fresh new fw_device.generation for each read > transaction. Hence it was able to continue reading in the middle of the > ROM even if a bus reset happened. However the device may have modified > the ROM during the reset. We would end up with a corrupt fetched ROM > image then. > > Although all of this is quite unlikely, it is not impossible. > Therefore we now restart reading the ROM if the bus generation changed. > > Side note: The barrier in read_rom(), inserted by patch "firewire: > enforce access order between generation and node ID" is not necessary > anymore because the sequence of calls > fw_device_init() -> > read_bus_info_block() -> > read_rom() > read_rom() > read_rom() > ... > will take care that generation is read before node_id, won't it? > > Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Based on a quick read through the code path, coupled with empirical evidence, yes, it appears safe to remove the barrier in read_rom().
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
-- Jarod Wilson jwilson@redhat.com
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