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ACPI: PCC: replace wait_for_completion()

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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: 77e2a04745 ("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>
This commit is contained in:
Huisong Li 2022-09-20 17:44:59 +08:00 committed by Rafael J. Wysocki
parent f890157e61
commit 91cefefb69
1 changed files with 21 additions and 2 deletions
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23
drivers/acpi/acpi_pcc.c
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@ -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);