usb: dwc2: host: Fix ahbcfg for rk3066
diff mbox

Message ID 1445384033-17050-1-git-send-email-dianders@chromium.org
State New
Headers show

Commit Message

Douglas Anderson Oct. 20, 2015, 11:33 p.m. UTC
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 <dianders@chromium.org>
---
 drivers/usb/dwc2/platform.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Heiko Stuebner Oct. 24, 2015, 1:08 p.m. UTC | #1
Am Dienstag, 20. Oktober 2015, 16:33:53 schrieb Douglas Anderson:
> 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 <dianders@chromium.org>

I gave this a spin on a rk3288-firefly, runs fine and doesn't have any 
negative effects, so

Tested-by: Heiko Stuebner <heiko@sntech.de>
John Youn Oct. 26, 2015, 10:57 p.m. UTC | #2
On 10/20/2015 4:35 PM, Douglas Anderson wrote:
> 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 <dianders@chromium.org>
> ---
>  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,
> 


Acked-by: John Youn <johnyoun@synopsys.com>


John
Wu Liang feng Oct. 30, 2015, 8:08 a.m. UTC | #3
On 10/21/2015 07:33 AM, Douglas Anderson wrote:
> 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 <dianders@chromium.org>
> ---
>   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,

Reviewed-by:  Liangfeng Wu <wulf@rock-chips.com>

Patch
diff mbox

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,