From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx48phIA7Ers7cZ5O3FT990P2l443c1G3JyvhfpRi3fwWIUmXK6ibyQ1KJ80n4s1Rlz14Z2me ARC-Seal: i=1; a=rsa-sha256; t=1524406413; cv=none; d=google.com; s=arc-20160816; b=ahmeOjJg8MHAIxyay+HXTTUZUD8B02jIpzNoCtrxjbB5zIJU5ZdFiQAZZ27RfBEwhR Im8oh1iMXbhMwkoFe8bHkb1CFjBnq3/MSG7XLcNl2RmLyqAZg0IeM8xqhzyKbZtOw4LL qQLE2zXJ5aDpxB+C7HX/r03C+m/p9SR5kLNL22KwSYomYp/lbvOhTL2PgCN3XWtDyl/B Z93tCTuamD7e4DYm2UYyM+ltTuJe1xnIu0bHWuz5YT/KGRCTaz2I5DL1mzEzGBztlwbL Fx+8xIVKZ406IKpCdjMecHzTD9J7y+7SPuiM/OJCBuWOGsDPHUKXb09tcFIgDHgIcDil SCzw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=IVSwu8RR8cWuefbsO5Ynb5b0uX5uxV4w2uDzW74ojhQ=; b=QX0/MS1EmCi8xJaAX8ZwFyMkSHu3K6Oj4u2o6UVC5DBhLxxe3LeHxOMV7JZWXDqn75 GjB7CwXeNORXNUgr67Oueuvs+MqQNe91cVYPH0TMpu9Lzr3DpWG0QcaJYWUJiIZaKkZ8 GVTSZMPNK2Mby9ah7uUiaAStC6x0NBvusUVCh/WjH+/46TW+9SEREh/SQJWpH1Hl6xSB 22CkV5+NaxGIjqL+iHu1Vf156H0/w1UmO9TsHpkJBC4ETw2u4fQR+ORQBzYlF2BBoFJ0 a7IG+ZXG3KgGqWDGHDrTMb1aJyUme7aPqKycyM6+PLUUtFyqwwWl/m+8LcpfNfZaCo3k EFnA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicholas Piggin , Michael Ellerman Subject: [PATCH 4.9 27/95] powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops Date: Sun, 22 Apr 2018 15:52:56 +0200 Message-Id: <20180422135211.547774444@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180422135210.432103639@linuxfoundation.org> References: <20180422135210.432103639@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598454959303912084?= X-GMAIL-MSGID: =?utf-8?q?1598455979788646097?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Piggin commit 3b8070335f751aac9f1526ae2e012e6f5b8b0f21 upstream. 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: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks") Depends-on: 34dd25de9fe3 ("powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops") Cc: stable@vger.kernel.org # v3.2+ Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/powernv/opal-nvram.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- 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 *bu 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)