diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 4bfbe55553f4..23d16a1ee878 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1002,14 +1002,14 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 	}
 
 	*val = 0;
+	size = GET_BIT_WIDTH(reg);
 
 	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
-		u32 width = GET_BIT_WIDTH(reg);
 		u32 val_u32;
 		acpi_status status;
 
 		status = acpi_os_read_port((acpi_io_address)reg->address,
-					   &val_u32, width);
+					   &val_u32, size);
 		if (ACPI_FAILURE(status)) {
 			pr_debug("Error: Failed to read SystemIO port %llx\n",
 				 reg->address);
@@ -1018,8 +1018,15 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 
 		*val = val_u32;
 		return 0;
-	} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0)
+	} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) {
+		/*
+		 * For registers in PCC space, the register size is determined
+		 * by the bit width field; the access size is used to indicate
+		 * the PCC subspace id.
+		 */
+		size = reg->bit_width;
 		vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
+	}
 	else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		vaddr = reg_res->sys_mem_vaddr;
 	else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
@@ -1028,8 +1035,6 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 		return acpi_os_read_memory((acpi_physical_address)reg->address,
 				val, reg->bit_width);
 
-	size = GET_BIT_WIDTH(reg);
-
 	switch (size) {
 	case 8:
 		*val = readb_relaxed(vaddr);
@@ -1044,8 +1049,13 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 		*val = readq_relaxed(vaddr);
 		break;
 	default:
-		pr_debug("Error: Cannot read %u bit width from PCC for ss: %d\n",
+		if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+			pr_debug("Error: Cannot read %u width from for system memory: 0x%llx\n",
+				reg->bit_width, reg->address);
+		} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+			pr_debug("Error: Cannot read %u bit width to PCC for ss: %d\n",
 			 reg->bit_width, pcc_ss_id);
+		}
 		return -EFAULT;
 	}
 
@@ -1063,12 +1073,13 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
 	struct cpc_reg *reg = &reg_res->cpc_entry.reg;
 
+	size = GET_BIT_WIDTH(reg);
+
 	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
-		u32 width = GET_BIT_WIDTH(reg);
 		acpi_status status;
 
 		status = acpi_os_write_port((acpi_io_address)reg->address,
-					    (u32)val, width);
+					    (u32)val, size);
 		if (ACPI_FAILURE(status)) {
 			pr_debug("Error: Failed to write SystemIO port %llx\n",
 				 reg->address);
@@ -1076,8 +1087,15 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 		}
 
 		return 0;
-	} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0)
+	} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) {
+		/*
+		 * For registers in PCC space, the register size is determined
+		 * by the bit width field; the access size is used to indicate
+		 * the PCC subspace id.
+		 */
+		size = reg->bit_width;
 		vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
+	}
 	else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		vaddr = reg_res->sys_mem_vaddr;
 	else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
@@ -1086,8 +1104,6 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 		return acpi_os_write_memory((acpi_physical_address)reg->address,
 				val, reg->bit_width);
 
-	size = GET_BIT_WIDTH(reg);
-
 	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		val = MASK_VAL(reg, val);
 
@@ -1105,8 +1121,13 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 		writeq_relaxed(val, vaddr);
 		break;
 	default:
-		pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n",
+		if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+			pr_debug("Error: Cannot write %u width from for system memory: 0x%llx\n",
+				reg->bit_width, reg->address);
+		} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+			pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n",
 			 reg->bit_width, pcc_ss_id);
+		}
 		ret_val = -EFAULT;
 		break;
 	}
