diff options
| author | Huisong Li <lihuisong@huawei.com> | 2022-09-20 11:44:59 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-09-22 21:08:03 +0200 |
| commit | 91cefefb699120efd0a5ba345d12626b688f86ce (patch) | |
| tree | b79f8c9bcba74735344cd6288592e6aa201b8286 /drivers/acpi/acpi_pcc.c | |
| parent | ACPI: PCC: Release resources on address space setup failure path (diff) | |
| download | linux-91cefefb699120efd0a5ba345d12626b688f86ce.tar.xz linux-91cefefb699120efd0a5ba345d12626b688f86ce.zip | |
ACPI: PCC: replace wait_for_completion()
Currently, the function waiting for completion of mailbox operation is
'wait_for_completion()'. The PCC method will be permanently blocked if
this mailbox message fails to execute. So this patch replaces it with
'wait_for_completion_timeout()'. And set the timeout interval to an
arbitrary retries on top of nominal to prevent the remote processor is
slow to respond to PCC commands.
Fixes: 77e2a04745ff ("ACPI: PCC: Implement OperationRegion handler for the PCC Type 3 subtype")
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/acpi_pcc.c')
| -rw-r--r-- | drivers/acpi/acpi_pcc.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/acpi/acpi_pcc.c b/drivers/acpi/acpi_pcc.c index 84f1ac416b57..16ba875e3293 100644 --- a/drivers/acpi/acpi_pcc.c +++ b/drivers/acpi/acpi_pcc.c @@ -23,6 +23,12 @@ #include <acpi/pcc.h> +/* + * Arbitrary retries in case the remote processor is slow to respond + * to PCC commands + */ +#define PCC_CMD_WAIT_RETRIES_NUM 500 + struct pcc_data { struct pcc_mbox_chan *pcc_chan; void __iomem *pcc_comm_addr; @@ -89,6 +95,7 @@ acpi_pcc_address_space_handler(u32 function, acpi_physical_address addr, { int ret; struct pcc_data *data = region_context; + u64 usecs_lat; reinit_completion(&data->done); @@ -99,8 +106,20 @@ acpi_pcc_address_space_handler(u32 function, acpi_physical_address addr, if (ret < 0) return AE_ERROR; - if (data->pcc_chan->mchan->mbox->txdone_irq) - wait_for_completion(&data->done); + if (data->pcc_chan->mchan->mbox->txdone_irq) { + /* + * pcc_chan->latency is just a Nominal value. In reality the remote + * processor could be much slower to reply. So add an arbitrary + * amount of wait on top of Nominal. + */ + usecs_lat = PCC_CMD_WAIT_RETRIES_NUM * data->pcc_chan->latency; + ret = wait_for_completion_timeout(&data->done, + usecs_to_jiffies(usecs_lat)); + if (ret == 0) { + pr_err("PCC command executed timeout!\n"); + return AE_TIME; + } + } mbox_client_txdone(data->pcc_chan->mchan, ret); |