[PATCH 5.5 082/176] scsi: zfcp: fix wrong data and display format of SFP+ temperature
From: Greg Kroah-Hartman
Date: Tue Mar 03 2020 - 12:47:50 EST
From: Benjamin Block <bblock@xxxxxxxxxxxxx>
commit a3fd4bfe85fbb67cf4ec1232d0af625ece3c508b upstream.
When implementing support for retrieval of local diagnostic data from the
FCP channel, the wrong data format was assumed for the temperature of the
local SFP+ connector. The Fibre Channel Link Services (FC-LS-3)
specification is not clear on the format of the stored integer, and only
after consulting the SNIA specification SFF-8472 did we realize it is
stored as two's complement. Thus, the used data and display format is
wrong, and highly misleading for users when the temperature should drop
below 0ÂC (however unlikely that may be).
To fix this, change the data format in `struct fsf_qtcb_bottom_port` from
unsigned to signed, and change the printf format string used to generate
`zfcp_sysfs_adapter_diag_sfp_temperature_show()` from `%hu` to `%hd`.
Link: https://lore.kernel.org/r/d6e3be5428da5c9490cfff4df7cae868bc9f1a7e.1582039501.git.bblock@xxxxxxxxxxxxx
Fixes: a10a61e807b0 ("scsi: zfcp: support retrieval of SFP Data via Exchange Port Data")
Fixes: 6028f7c4cd87 ("scsi: zfcp: introduce sysfs interface for diagnostics of local SFP transceiver")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.5+
Reviewed-by: Jens Remus <jremus@xxxxxxxxxxxxx>
Reviewed-by: Fedor Loshakov <loshakov@xxxxxxxxxxxxx>
Reviewed-by: Steffen Maier <maier@xxxxxxxxxxxxx>
Signed-off-by: Benjamin Block <bblock@xxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/s390/scsi/zfcp_fsf.h | 2 +-
drivers/s390/scsi/zfcp_sysfs.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -410,7 +410,7 @@ struct fsf_qtcb_bottom_port {
u8 cb_util;
u8 a_util;
u8 res2;
- u16 temperature;
+ s16 temperature;
u16 vcc;
u16 tx_bias;
u16 tx_power;
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -800,7 +800,7 @@ static ZFCP_DEV_ATTR(adapter_diag, b2b_c
static ZFCP_DEV_ATTR(adapter_diag_sfp, _name, 0400, \
zfcp_sysfs_adapter_diag_sfp_##_name##_show, NULL)
-ZFCP_DEFINE_DIAG_SFP_ATTR(temperature, temperature, 5, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(temperature, temperature, 6, "%hd");
ZFCP_DEFINE_DIAG_SFP_ATTR(vcc, vcc, 5, "%hu");
ZFCP_DEFINE_DIAG_SFP_ATTR(tx_bias, tx_bias, 5, "%hu");
ZFCP_DEFINE_DIAG_SFP_ATTR(tx_power, tx_power, 5, "%hu");