Return-Path: Received: from mail-pg0-f66.google.com ([74.125.83.66]:34590 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932080AbeENQAU (ORCPT ); Mon, 14 May 2018 12:00:20 -0400 Received: by mail-pg0-f66.google.com with SMTP id k2-v6so95332pgc.1 for ; Mon, 14 May 2018 09:00:20 -0700 (PDT) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin , stable@vger.kernel.org Subject: [PATCH 2/2] powerpc/powernv: Fix NVRAM sleep in invalid context when crashing Date: Tue, 15 May 2018 01:59:47 +1000 Message-Id: <20180514155947.22753-3-npiggin@gmail.com> In-Reply-To: <20180514155947.22753-1-npiggin@gmail.com> References: <20180514155947.22753-1-npiggin@gmail.com> Sender: stable-owner@vger.kernel.org List-ID: Similarly to opal_event_shutdown, opal_nvram_write can be called in the crash path with irqs disabled. Special case the delay to avoid sleeping in invalid context. Cc: stable@vger.kernel.org # v3.2 Fixes: 3b8070335f ("powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops") Signed-off-by: Nicholas Piggin --- arch/powerpc/platforms/powernv/opal-nvram.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c index 1bceb95f422d..5584247f5029 100644 --- a/arch/powerpc/platforms/powernv/opal-nvram.c +++ b/arch/powerpc/platforms/powernv/opal-nvram.c @@ -44,6 +44,10 @@ static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index) return count; } +/* + * This can be called in the panic path with interrupts off, so use + * mdelay in that case. + */ static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index) { s64 rc = OPAL_BUSY; @@ -58,10 +62,16 @@ 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) { - msleep(OPAL_BUSY_DELAY_MS); + if (in_interrupt() || irqs_disabled()) + mdelay(OPAL_BUSY_DELAY_MS); + else + msleep(OPAL_BUSY_DELAY_MS); opal_poll_events(NULL); } else if (rc == OPAL_BUSY) { - msleep(OPAL_BUSY_DELAY_MS); + if (in_interrupt() || irqs_disabled()) + mdelay(OPAL_BUSY_DELAY_MS); + else + msleep(OPAL_BUSY_DELAY_MS); } } -- 2.17.0