From a3fd4bfe85fbb67cf4ec1232d0af625ece3c508b Mon Sep 17 00:00:00 2001 From: Benjamin Block Date: Wed, 19 Feb 2020 16:09:25 +0100 Subject: scsi: zfcp: fix wrong data and display format of SFP+ temperature MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 0°C (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@linux.ibm.com 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: # 5.5+ Reviewed-by: Jens Remus Reviewed-by: Fedor Loshakov Reviewed-by: Steffen Maier Signed-off-by: Benjamin Block Signed-off-by: Martin K. Petersen --- drivers/s390/scsi/zfcp_sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/s390/scsi/zfcp_sysfs.c') diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c index 494b9fe9cc94..a711a0d15100 100644 --- 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_credit, 0400, 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"); -- cgit