On Tue, Jan 28, 2025 at 01:37:51PM +0530, Mukesh Ojha wrote:
> When some client process A call pdr_add_lookup() to add the look up for
> the service and does schedule locator work, later a process B got a new
> server packet indicating locator is up and call pdr_locator_new_server()
> which eventually sets pdr->locator_init_complete to true which process A
> sees and takes list lock and queries domain list but it will timeout due
> to deadlock as the response will queued to the same qmi->wq and it is
> ordered workqueue and process B is not able to complete new server
> request work due to deadlock on list lock.
>
> Process A Process B
>
> process_scheduled_works()
> pdr_add_lookup() qmi_data_ready_work()
> process_scheduled_works() pdr_locator_new_server()
> pdr->locator_init_complete=true;
> pdr_locator_work()
> mutex_lock(&pdr->list_lock);
>
> pdr_locate_service() mutex_lock(&pdr->list_lock);
>
> pdr_get_domain_list()
> pr_err("PDR: %s get domain list
> txn wait failed: %d\n",
> req->service_name,
> ret);
>
> Fix it by removing the unnecessary list iteration as the list iteration
> is already being done inside locator work, so avoid it here and just
> call schedule_work() here.
>
> Signed-off-by: Saranya R <quic_sarar@xxxxxxxxxxx>
> Signed-off-by: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
Missing Fixes tag.
> ---
> drivers/soc/qcom/pdr_interface.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
--
With best wishes
Dmitry
