Path: csiph.com!news.redatomik.org!aioe.org!bofh.it!news.nic.it!robomod From: "Levin, Alexander (Sasha Levin)" Newsgroups: linux.kernel Subject: [PATCH review for 4.9 03/50] watchdog: kempld: fix gcc-4.3 build Date: Mon, 25 Sep 2017 03:40:02 +0200 Message-ID: References: X-Original-To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=verizon.com; i=@verizon.com; q=dns/txt; s=corp; t=1506302050; x=1537838050; h=from:cc:to:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=/t51gnuu60uLiyHYMUimXzUkVdMJR6RffjyqhTHnitw=; b=iwjcLRzgVtBqv2QG/RQWNWVV3Wv9O6jIxqMfIA9i4dTuzH9oQD8chh31 caidXwnGgl51X5Acwctq5NGNfAhWLnciTfAsc+HE3SQA2vrSPFW3a8VY2 lEILXFAlHuXA6J09Nmqklmyv7uw6nF4TGYhZMZEowQScrEuCwdBKKM4dT s=; Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=verizon.com; i=@verizon.com; q=dns/txt; s=corp; t=1506301963; x=1537837963; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=/t51gnuu60uLiyHYMUimXzUkVdMJR6RffjyqhTHnitw=; b=mCbQsiaIoukJMoLKqHAWNuC7dA5EyPpLvR2v8h5++TzvlP9E69CPnNRW b18BQdFlj71cJ2RXzEHrVjpHR58njkcwoPcViEnbsa8+b7l5RcDr/Vslr WVtvqY3HHtDg+6cXq/kmAyqLUIPCpwDUvj8l0T6ms0dpNxbKq5Ol4R3gg 0=; Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=verizon.com; i=@verizon.com; q=dns/txt; s=corp; t=1506301963; x=1537837963; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=/t51gnuu60uLiyHYMUimXzUkVdMJR6RffjyqhTHnitw=; b=mCbQsiaIoukJMoLKqHAWNuC7dA5EyPpLvR2v8h5++TzvlP9E69CPnNRW b18BQdFlj71cJ2RXzEHrVjpHR58njkcwoPcViEnbsa8+b7l5RcDr/Vslr WVtvqY3HHtDg+6cXq/kmAyqLUIPCpwDUvj8l0T6ms0dpNxbKq5Ol4R3gg 0=; X-Host: discovery.odc.vzwcorp.com Thread-Topic: [PATCH review for 4.9 03/50] watchdog: kempld: fix gcc-4.3 build Thread-Index: AQHTNZtiY/vOu8McFUiDbTbYwY0PwA== Accept-Language: en-US Content-Language: en-US X-Ms-Exchange-Messagesentrepresentingtype: 1 X-Ms-Exchange-Transport-Fromentityheader: Hosted X-Originating-IP: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 52 Organization: linux.* mail to news gateway X-Original-Cc: Arnd Bergmann , Guenter Roeck , "Levin, Alexander (Sasha Levin)" X-Original-Date: Mon, 25 Sep 2017 01:12:40 +0000 X-Original-Message-ID: <20170925011225.10029-3-alexander.levin@verizon.com> X-Original-References: <20170925011225.10029-1-alexander.levin@verizon.com> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1738687 From: Arnd Bergmann [ Upstream commit 3736d4eb6af37492aeded7fec0072dedd959c842 ] gcc-4.3 can't decide whether the constant value in kempld_prescaler[PRESCALER_21] is built-time constant or not, and gets confused by the logic in do_div(): drivers/watchdog/kempld_wdt.o: In function `kempld_wdt_set_stage_timeout': kempld_wdt.c:(.text.kempld_wdt_set_stage_timeout+0x130): undefined referenc= e to `__aeabi_uldivmod' This adds a call to ACCESS_ONCE() to force it to not consider it to be constant, and leaves the more efficient normal case in place for modern compilers, using an #ifdef to annotate why we do this hack. Signed-off-by: Arnd Bergmann Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/watchdog/kempld_wdt.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/kempld_wdt.c b/drivers/watchdog/kempld_wdt.c index 8e302d0e346c..3efa295ac627 100644 --- a/drivers/watchdog/kempld_wdt.c +++ b/drivers/watchdog/kempld_wdt.c @@ -140,12 +140,19 @@ static int kempld_wdt_set_stage_timeout(struct kempld= _wdt_data *wdt_data, unsigned int timeout) { struct kempld_device_data *pld =3D wdt_data->pld; - u32 prescaler =3D kempld_prescaler[PRESCALER_21]; + u32 prescaler; u64 stage_timeout64; u32 stage_timeout; u32 remainder; u8 stage_cfg; =20 +#if GCC_VERSION < 40400 + /* work around a bug compiling do_div() */ + prescaler =3D READ_ONCE(kempld_prescaler[PRESCALER_21]); +#else + prescaler =3D kempld_prescaler[PRESCALER_21]; +#endif + if (!stage) return -EINVAL; =20 --=20 2.11.0