linux-kernel - [PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1479115631-20137-3-git-send-email-wulf@rock-chips.com>
Date:   Mon, 14 Nov 2016 17:27:11 +0800
From:   William Wu <wulf@...k-chips.com>
To:     kishon@...com, heiko@...ech.de
Cc:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-rockchip@...ts.infradead.org, devicetree@...r.kernel.org,
        robh+dt@...nel.org, frank.wang@...k-chips.com,
        huangtao@...k-chips.com, dianders@...gle.com,
        briannorris@...gle.com, groeck@...gle.com, wulf@...k-chips.com
Subject: [PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time

We found that the system crashed due to 480MHz output clock of
USB2 PHY was unstable after clock had been enabled by gpu module.

Theoretically, 1 millisecond is a critical value for 480MHz
output clock stable time, so we try to change the delay time
to 1.2 millisecond to avoid this issue.

And the commit ed907fb1d7c3 ("phy: rockchip-inno-usb2: correct
clk_ops callback") used prepare callbacks instead of enable
callbacks to support gate a clk if the operation may sleep. So
we can switch from delay to sleep functions.

Signed-off-by: William Wu <wulf@...k-chips.com>
---
Changes in v3:
- fix kbuild test error: too few arguments to function 'usleep_range'

Changes in v2:
- use usleep_range() function instead of mdelay()

 drivers/phy/phy-rockchip-inno-usb2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/phy/phy-rockchip-inno-usb2.c b/drivers/phy/phy-rockchip-inno-usb2.c
index 365e077..0e52b25 100644
--- a/drivers/phy/phy-rockchip-inno-usb2.c
+++ b/drivers/phy/phy-rockchip-inno-usb2.c
@@ -166,7 +166,7 @@ static int rockchip_usb2phy_clk480m_prepare(struct clk_hw *hw)
 			return ret;
 
 		/* waitting for the clk become stable */
-		mdelay(1);
+		usleep_range(1200, 1300);
 	}
 
 	return 0;
-- 
2.0.0