From: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
Date: Tue, 27 Feb 2018 17:19:52 -0600
Subject: PCI/ASPM: Declare threshold_ns as u32, not u64
Git-commit: f51af8a63c5f633b572d00319ecdfa31f266b8fb
Patch-mainline: 4.17-rc1
References: git-fixes
aspm_calc_l1ss_info() computes l1_2_threshold in microseconds as:
l1_2_threshold = 2 + 4 + t_common_mode + t_power_on;
where t_common_mode is at most 255us:
PCI_L1SS_CAP_CM_RESTORE_TIME 0x0000ff00 <-- 8 bits; <256us
and t_power_on is at most 31 * 100us = 3100us:
PCI_L1SS_CAP_P_PWR_ON_VALUE 0x00f80000 <-- 5 bits; <32
PCI_L1SS_CAP_P_PWR_ON_SCALE 0x00030000 <-- *2us, *10us, or *100us
So l1_2_threshold is at most 2 + 4 + 255 + 3100 = 3361, which means
threshold_ns is at most 3361 * 1000 = 3361000, which easily fits in a
u32.
Declare threshold_ns as u32, not u64. This fixes a Coverity warning.
Addresses-Coverity-ID: 1462501
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/pci/pcie/aspm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -321,7 +321,7 @@ static u32 calc_l1ss_pwron(struct pci_de
static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value)
{
- u64 threshold_ns = threshold_us * 1000;
+ u32 threshold_ns = threshold_us * 1000;
/* See PCIe r3.1, sec 7.33.3 and sec 6.18 */
if (threshold_ns < 32) {