From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752865AbbJTXfL (ORCPT ); Tue, 20 Oct 2015 19:35:11 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:35631 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751889AbbJTXfJ (ORCPT ); Tue, 20 Oct 2015 19:35:09 -0400 From: Douglas Anderson To: John Youn , balbi@ti.com Cc: Wu Liang Feng , Yunzhi Li , =?UTF-8?q?Heiko=20St=C3=BCbner?= , linux-rockchip@lists.infradead.org, Julius Werner , Douglas Anderson , johnyoun@synopsys.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] usb: dwc2: host: Fix ahbcfg for rk3066 Date: Tue, 20 Oct 2015 16:33:53 -0700 Message-Id: <1445384033-17050-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 2.6.0.rc2.230.g3dd15c0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The comment for ahbcfg for rk3066 parameters (also used for rk3288) claimed that ahbcfg was INCR16, but it wasn't. Since the bits weren't shifted properly, the 0x7 ended up being masked and we ended up programming 0x3 for the HBstLen. Let's set it to INCR16 properly. As per Wu Liang Feng at Rockchip this may increase transmission efficiency. I did blackbox tests with writing 0s to a USB-based SD reader (forcefully capping CPU Freq to try to measure efficiency): cd /sys/devices/system/cpu/cpu0/cpufreq echo userspace > scaling_governor echo 126000 > scaling_setspeed for i in $(seq 10); do dd if=/dev/zero of=/dev/sdb bs=1M count=750 done With the above tests I found that speeds went from ~15MB/s to ~18MB/s. Note that most other tests I did (including reading from the same USB reader) didn't show any difference in performance. Signed-off-by: Douglas Anderson --- drivers/usb/dwc2/platform.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c index 5859b0f..e61d773 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -108,7 +108,8 @@ static const struct dwc2_core_params params_rk3066 = { .host_ls_low_power_phy_clk = -1, .ts_dline = -1, .reload_ctl = -1, - .ahbcfg = 0x7, /* INCR16 */ + .ahbcfg = GAHBCFG_HBSTLEN_INCR16 << + GAHBCFG_HBSTLEN_SHIFT, .uframe_sched = -1, .external_id_pin_ctl = -1, .hibernation = -1, -- 2.6.0.rc2.230.g3dd15c0