From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com [IPv6:2607:f8b0:400e:c00::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40L58N5WnKzDqyH for ; Tue, 10 Apr 2018 21:50:28 +1000 (AEST) Received: by mail-pf0-x244.google.com with SMTP id p15so8075981pff.11 for ; Tue, 10 Apr 2018 04:50:28 -0700 (PDT) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin , Benjamin Herrenschmidt Subject: [PATCH 3/3] powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops Date: Tue, 10 Apr 2018 21:49:33 +1000 Message-Id: <20180410114933.24581-4-npiggin@gmail.com> In-Reply-To: <20180410114933.24581-1-npiggin@gmail.com> References: <20180410114933.24581-1-npiggin@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The OPAL NVRAM driver does not sleep in case it gets OPAL_BUSY or OPAL_BUSY_EVENT from firmware, which causes large scheduling latencies, and various lockup errors to trigger (again, BMC reboot can cause it). Fix this by converting it to the standard form OPAL_BUSY loop that sleeps. Fixes: 628daa8d5abfd ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks") Cc: Benjamin Herrenschmidt Signed-off-by: Nicholas Piggin --- arch/powerpc/platforms/powernv/opal-nvram.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c index ba2ff06a2c98..1bceb95f422d 100644 --- a/arch/powerpc/platforms/powernv/opal-nvram.c +++ b/arch/powerpc/platforms/powernv/opal-nvram.c @@ -11,6 +11,7 @@ #define DEBUG +#include #include #include #include @@ -56,8 +57,12 @@ static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index) while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { rc = opal_write_nvram(__pa(buf), count, off); - if (rc == OPAL_BUSY_EVENT) + if (rc == OPAL_BUSY_EVENT) { + msleep(OPAL_BUSY_DELAY_MS); opal_poll_events(NULL); + } else if (rc == OPAL_BUSY) { + msleep(OPAL_BUSY_DELAY_MS); + } } if (rc) -- 2.17.0