From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Dalessandro Subject: [PATCH for-next 3/7] IB/hfi1: Correct unnecessary acquisition of HW mutex Date: Mon, 09 Oct 2017 12:38:04 -0700 Message-ID: <20171009193801.6965.7420.stgit@scvm10.sc.intel.com> References: <20171009161736.6965.75352.stgit@scvm10.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171009161736.6965.75352.stgit-9QXIwq+3FY+1XWohqUldA0EOCMrvLtNR@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mike Marciniszyn , Grzegorz Morys List-Id: linux-rdma@vger.kernel.org From: Grzegorz Morys Avoid acquiring already acquired hardware mutex and releasing the unacquired one as these are redundant operations. Add printouts for such situations to help detect potential errors within the driver. Reviewed-by: Mike Marciniszyn Signed-off-by: Grzegorz Morys Signed-off-by: Dennis Dalessandro --- drivers/infiniband/hw/hfi1/firmware.c | 19 +++++++++++++++++-- 1 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/firmware.c b/drivers/infiniband/hw/hfi1/firmware.c index b10781d..148a2c7 100644 --- a/drivers/infiniband/hw/hfi1/firmware.c +++ b/drivers/infiniband/hw/hfi1/firmware.c @@ -1424,7 +1424,14 @@ int acquire_hw_mutex(struct hfi1_devdata *dd) unsigned long timeout; int try = 0; u8 mask = 1 << dd->hfi1_id; - u8 user; + u8 user = (u8)read_csr(dd, ASIC_CFG_MUTEX); + + if (user == mask) { + dd_dev_info(dd, + "Hardware mutex already acquired, mutex mask %u\n", + (u32)mask); + return 0; + } retry: timeout = msecs_to_jiffies(HM_TIMEOUT) + jiffies; @@ -1455,7 +1462,15 @@ int acquire_hw_mutex(struct hfi1_devdata *dd) void release_hw_mutex(struct hfi1_devdata *dd) { - write_csr(dd, ASIC_CFG_MUTEX, 0); + u8 mask = 1 << dd->hfi1_id; + u8 user = (u8)read_csr(dd, ASIC_CFG_MUTEX); + + if (user != mask) + dd_dev_warn(dd, + "Unable to release hardware mutex, mutex mask %u, my mask %u\n", + (u32)user, (u32)mask); + else + write_csr(dd, ASIC_CFG_MUTEX, 0); } /* return the given resource bit(s) as a mask for the given HFI */ -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html