From mboxrd@z Thu Jan 1 00:00:00 1970 From: wulf@rock-chips.com (William Wu) Date: Mon, 14 Nov 2016 15:01:51 +0800 Subject: [PATCH v2 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time In-Reply-To: <1479106911-16049-1-git-send-email-wulf@rock-chips.com> References: <1479106911-16049-1-git-send-email-wulf@rock-chips.com> Message-ID: <1479106911-16049-3-git-send-email-wulf@rock-chips.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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..578290b 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); } return 0; -- 2.0.0