[PATCH] usb: dwc3: Update nominal max votes for qcom usb

[PATCH] usb: dwc3: Update nominal max votes for qcom usb

[Akash Kumar]

Increase nominal max votes to improve DDR performance and USB audio
use case handling.

Currently, Bandwidth vote for max nominal value is set to 2500,
requiring DDR to run at 1GHz under normal load.

DDR is allowed to run under nominal range at 1.5GHz, which is
consistent across all targets. However, with the current nominal
vote, glitches are observed during multiple audio use cases over USB.
Update the nominal vote to allow DDR to run more
efficiently, enabling simultaneous multiple USB audio use cases
without glitches.

With the existing vote, throughput is around 125MB/s. The updated nominal
value increases throughput to 145MB/s.

Benefits:

Enhanced performance and stability for multiple USB audio use cases.
Improved overall system efficiency with higher throughput. Slight
improvement in the audio KPI from 17.9ms to 16.6ms RTD-USBC.
By implementing this change, we expect to see significant improvements in
both performance and stability, particularly for USB audio use cases,
leading to a more efficient system overall.

Signed-off-by: Akash Kumar <akakum@qti.qualcomm.com>
---
 drivers/usb/dwc3/dwc3-qcom.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index f43f73ac36ff..aa43a03f3c7f 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -46,9 +46,9 @@
 #define USB_MEMORY_AVG_HS_BW MBps_to_icc(240)
 #define USB_MEMORY_PEAK_HS_BW MBps_to_icc(700)
 #define USB_MEMORY_AVG_SS_BW  MBps_to_icc(1000)
-#define USB_MEMORY_PEAK_SS_BW MBps_to_icc(2500)
-#define APPS_USB_AVG_BW 0
-#define APPS_USB_PEAK_BW MBps_to_icc(40)
+#define USB_MEMORY_PEAK_SS_BW MBps_to_icc(5500)
+#define APPS_USB_AVG_BW 40
+#define APPS_USB_PEAK_BW MBps_to_icc(80)
 
 /* Qualcomm SoCs with multiport support has up to 4 ports */
 #define DWC3_QCOM_MAX_PORTS	4
-- 
2.43.0

Re: [PATCH] usb: dwc3: Update nominal max votes for qcom usb

[Dmitry Baryshkov]

On Thu, Jun 11, 2026 at 01:48:21PM +0530, Akash Kumar wrote:
> Increase nominal max votes to improve DDR performance and USB audio
> use case handling.
> 
> Currently, Bandwidth vote for max nominal value is set to 2500,
> requiring DDR to run at 1GHz under normal load.

How comes? Please explain the math here.

> 
> DDR is allowed to run under nominal range at 1.5GHz, which is
> consistent across all targets. However, with the current nominal

Which targets? Does it cover Agatti? SDX55? IPQ8064?

> vote, glitches are observed during multiple audio use cases over USB.
> Update the nominal vote to allow DDR to run more
> efficiently, enabling simultaneous multiple USB audio use cases
> without glitches.
> 
> With the existing vote, throughput is around 125MB/s. The updated nominal
> value increases throughput to 145MB/s.
> 
> Benefits:
> 
> Enhanced performance and stability for multiple USB audio use cases.
> Improved overall system efficiency with higher throughput. Slight
> improvement in the audio KPI from 17.9ms to 16.6ms RTD-USBC.

What kind of KPI is this?

> By implementing this change, we expect to see significant improvements in

Expect or observe?

> both performance and stability, particularly for USB audio use cases,
> leading to a more efficient system overall.
> 
> Signed-off-by: Akash Kumar <akakum@qti.qualcomm.com>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index f43f73ac36ff..aa43a03f3c7f 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -46,9 +46,9 @@
>  #define USB_MEMORY_AVG_HS_BW MBps_to_icc(240)
>  #define USB_MEMORY_PEAK_HS_BW MBps_to_icc(700)
>  #define USB_MEMORY_AVG_SS_BW  MBps_to_icc(1000)
> -#define USB_MEMORY_PEAK_SS_BW MBps_to_icc(2500)
> -#define APPS_USB_AVG_BW 0
> -#define APPS_USB_PEAK_BW MBps_to_icc(40)
> +#define USB_MEMORY_PEAK_SS_BW MBps_to_icc(5500)
> +#define APPS_USB_AVG_BW 40

MBps_to_icc(40)

> +#define APPS_USB_PEAK_BW MBps_to_icc(80)

You've tried to explain, why we change USB_MEMORY_PEAK_SS_BW. Why are
you chahing APPS_USB_*_BW?

>  
>  /* Qualcomm SoCs with multiport support has up to 4 ports */
>  #define DWC3_QCOM_MAX_PORTS	4
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry