From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49/F179InF9zz3ZyZTCymrqAGBZ7MGRxDNxPedaDAhLhGJG875MurSWnz2atZO9nVA/1ySo ARC-Seal: i=1; a=rsa-sha256; t=1524405949; cv=none; d=google.com; s=arc-20160816; b=rA6q2Li5zwqbfVCTOk2Zvvfjr5K0Ky1zRMyT2PFnAa3ewteool8YYRyp9okzjIETxC v+IFW5+6fVLrdAJWUDT/iKhPSt5VraZYmDdq0o/Rgam9LLMIARhP0NclXrWfQLl3UFDZ UFdkqCAZop3/5yglW5e7FB7K6qkv9NfsHk1xww8ByuzPipLQ1Ot3L0wT7SuUU9orzIfe 6LfQ3jhguLaahn9/jiVsKmm4sQOK4GNbcxapmrUQ4jbOUmXS9N7AmNNnyKgxkRBXXSSv yHc2zW62MmOc8h3RbzrS+9k528unrgRYfl5kZ3F7WD2ia9/CCTgHROb6bW5mVagDztSi Tt+Q== 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=WrNMpaabPKD8W3DLv6cmhZHuVC5giMKTxqNCyfuJ5NA=; b=Jeb4ZKyxg5yXqTvosItC/U8jWdG3OUivdjVvPTnrkyVrief9yRgEstlEyWRAguI0uz YdsKUYxT9Rtx6NH+N/oUoZhD2jsvsYfvbcCPXPQJD3PtJ1W4QNOXghUJ1cNXqty8fAYu 1XgSnEOQQbakY466maEZE7nyFzHra7CdtZtpdIdyqBjusb1OUYpok/6DfAMp8tAg/5ZI w2xYHZEA54Itejqfz9V4T+ygFTg9SyfrAGkDdRT4QTOKwTx59sjZYdQtN2iTBaNKTjmW PrZjUmOFKGX6P4mAj5has9T3BWxYc/WLgpHGKxrMdvMtwTrMasEfcUsIOLClRQ0UbF/V j3ig== 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 4.14 057/164] powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops Date: Sun, 22 Apr 2018 15:52:04 +0200 Message-Id: <20180422135137.776144260@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180422135135.400265110@linuxfoundation.org> References: <20180422135135.400265110@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?1598455493165389538?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-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)