Hi, On 26.11.21 at 17:09, Russell King (Oracle) wrote: > On Fri, Nov 26, 2021 at 03:39:25PM +0100, Lino Sanfilippo wrote: >> The driver attempts to request and release the IO memory region for a uart >> port twice: >> >> First during the probe() function devm_ioremap_resource() is used to >> allocate and map the ports memory. >> Then a combo of pl011_config_port() and pl011_release_port() is used to >> request/release the same memory area. These functions are called by the >> serial core as soon as the uart is registered/unregistered. >> >> However since the allocation request via devm_ioremap_resource() already >> succeeds, the attempt to claim the memory again via pl011_config_port() >> fails. This failure remains unnoticed, since the concerning return value is >> not evaluated. >> Later at module unload also the attempt to release the unclaimed memory >> in pl011_release_port() fails. This time the failure results in a “Trying >> to free nonexistent resource" warning printed by the serial core. >> >> Fix these issues by removing the callbacks that implement the redundant >> memory allocation/release. > > I think you will also need the verify_port method to also deny changing > port->mapbase. > Right, I will add this, thanks for the hint! Regards, Lino
