Messages in this thread | | | From | Rayagonda Kokatanur <> | Date | Mon, 27 Jul 2020 10:02:09 +0530 | Subject | Re: [PATCH] i2c: iproc: fix race between client unreg and isr |
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On Sat, Jul 25, 2020 at 3:48 PM Wolfram Sang <wsa@kernel.org> wrote: > > > > I think the following sequence needs to be implemented to make this > > safe, i.e., after 'synchronize_irq', no further slave interrupt will be > > fired. > > > > In 'bcm_iproc_i2c_unreg_slave': > > > > 1. Set an atomic variable 'unreg_slave' (I'm bad in names so please come > > up with a better name than this) > > > > 2. Disable all slave interrupts > > > > 3. synchronize_irq > > > > 4. Set slave to NULL > > > > 5. Erase slave addresses > > What about this in unreg_slave? > > 1. disable_irq() > This includes synchronize_irq() and avoids the race. Because irq > will be masked at interrupt controller level, interrupts coming > in at the I2C IP core level should still be pending once we > reenable the irq. > > 2. disable all slave interrupts > > 3. enable_irq() > > 4. clean up the rest (pointer, address) > > Or am I overlooking something?
This sequence will take care of all cases.
@Dhananjay Phadke is it possible to verify this from your side once.
Best regards, Raaygonda
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