1 files changed, 26 insertions, 4 deletions

diff --git a/drivers/acpi/acpi_pcc.c b/drivers/acpi/acpi_pcc.c
index 41e3ebd204ff..3e252be047b8 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	500ULL
+
 struct pcc_data {
 	struct pcc_mbox_chan *pcc_chan;
 	void __iomem *pcc_comm_addr;
@@ -31,7 +37,7 @@ struct pcc_data {
 	struct acpi_pcc_info ctx;
 };
 
-struct acpi_pcc_info pcc_ctx;
+static struct acpi_pcc_info pcc_ctx;
 
 static void pcc_rx_callback(struct mbox_client *cl, void *m)
 {
@@ -63,6 +69,7 @@ acpi_pcc_address_space_setup(acpi_handle region_handle, u32 function,
 	if (IS_ERR(data->pcc_chan)) {
 		pr_err("Failed to find PCC channel for subspace %d\n",
 		       ctx->subspace_id);
+		kfree(data);
 		return AE_NOT_FOUND;
 	}
 
@@ -72,6 +79,8 @@ acpi_pcc_address_space_setup(acpi_handle region_handle, u32 function,
 	if (!data->pcc_comm_addr) {
 		pr_err("Failed to ioremap PCC comm region mem for %d\n",
 		       ctx->subspace_id);
+		pcc_mbox_free_channel(data->pcc_chan);
+		kfree(data);
 		return AE_NO_MEMORY;
 	}
 
@@ -86,6 +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);
 
@@ -96,10 +106,22 @@ 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);
+	mbox_chan_txdone(data->pcc_chan->mchan, ret);
 
 	memcpy_fromio(value, data->pcc_comm_addr, data->ctx.length);