Re: [PATCHv2] dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lock

From: Sergey Senozhatsky
Date: Wed Aug 23 2023 - 23:16:37 EST


On (23/08/16 11:32), Sergey Senozhatsky wrote:
> __dma_entry_alloc_check_leak() calls into printk -> serial console
> output (qcom geni) and grabs port->lock under free_entries_lock
> spin lock, which is a reverse locking dependency chain as qcom_geni
> IRQ handler can call into dma-debug code and grab free_entries_lock
> under port->lock.
>
> Move __dma_entry_alloc_check_leak() call out of free_entries_lock
> scope so that we don't acquire serial console's port->lock under it.

Hello folks,

Have you got a chance to take a look at the patch?