Re: [cip-dev] [RFC PATCH 4.19.y-cip 24/50] PCI: endpoint: Replace spinlock with mutex

Pavel Machek
2020-10-20T20:43:38Z

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Hi!

> commit 3d3248dbd018502f654064c78efcd2e165ab3486 upstream.
>
> The pci_epc_ops is not intended to be invoked from interrupt context.
> Hence replace spin_lock_irqsave and spin_unlock_irqrestore with
> mutex_lock and mutex_unlock respectively.

Could I get some kind of explanation why this is good idea?

As long as code protected by the locks does not sleep, spinlocks are
okay... (but they should not need "_irqsave" variants).

They are likely to have better performance, too, when protected code
is small and fast.

Best regards,
Pavel
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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