[PATCH 5.3 081/197] net: aquantia: temperature retrieval fix

From: Greg Kroah-Hartman
Date: Sun Oct 27 2019 - 17:20:54 EST


From: Igor Russkikh <Igor.Russkikh@xxxxxxxxxxxx>

[ Upstream commit 06b0d7fe7e5ff3ba4c7e265ef41135e8bcc232bb ]

Chip temperature is a two byte word, colocated internally with cable
length data. We do all readouts from HW memory by dwords, thus
we should clear extra high bytes, otherwise temperature output
gets weird as soon as we attach a cable to the NIC.

Fixes: 8f8940118654 ("net: aquantia: add infrastructure to readout chip temperature")
Tested-by: Holger HoffstÃtte <holger@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Igor Russkikh <igor.russkikh@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils_fw2x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils_fw2x.c
+++ b/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils_fw2x.c
@@ -337,7 +337,7 @@ static int aq_fw2x_get_phy_temp(struct a
/* Convert PHY temperature from 1/256 degree Celsius
* to 1/1000 degree Celsius.
*/
- *temp = temp_res * 1000 / 256;
+ *temp = (temp_res & 0xFFFF) * 1000 / 256;

return 0;
}