| Message ID | 20180228131658.11883-1-abrodkin@synopsys.com |
|---|---|
| State | Accepted, archived |
| Commit | 42637fdae833f8c3e8a0270ea7e74152cbd8ef38 |
| Delegated to: | Marek Vasut |
| Headers | show |
| Series | [U-Boot] usb: dwc2: Allow selection of data buffer size | expand |
On 02/28/2018 02:16 PM, Alexey Brodkin wrote: > If we use hardware with very small RAM (let's consider just a couple > of hundreds of kB but not megabytes) it is not super convenient to lose > 64kB for statically allocated bufer which most probably won't be used > as big as it is. Typically we'll have much shorter data packages to > excahnge and in the worst case longer packets will be split on separate > transactions. > > For those corner-cases user will be able to set his buffer size of > choice via USB_DWC2_BUFFER_SIZE option in menuconfig. > > By default we'll use 64 kB as it was hard-coeded before so existing > users shouldn't be affected at all. > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> > Cc: Marek Vasut <marex@denx.de> Applied, thanks
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig index 90b2f78ec7d9..a7249b7511f4 100644 --- a/drivers/usb/host/Kconfig +++ b/drivers/usb/host/Kconfig @@ -245,3 +245,15 @@ config USB_DWC2 Hi-Speed (480 Mbps), Full-Speed (12 Mbps), and Low-Speed (1.5 Mbps) operation is compliant to the controller Supplement. If you want to enable this controller in host mode, say Y. + +if USB_DWC2 +config USB_DWC2_BUFFER_SIZE + int "Data buffer size in kB" + default 64 + ---help--- + By default 64 kB buffer is used but if amount of RAM avaialble on + the target is not enough to accommodate allocation of buffer of + that size it is possible to shrink it. Smaller sizes should be fine + because larger transactions could be split in smaller ones. + +endif # USB_DWC2 diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c index 0efe645044c5..e436c711e720 100644 --- a/drivers/usb/host/dwc2.c +++ b/drivers/usb/host/dwc2.c @@ -25,7 +25,7 @@ DECLARE_GLOBAL_DATA_PTR; #define DWC2_HC_CHANNEL 0 #define DWC2_STATUS_BUF_SIZE 64 -#define DWC2_DATA_BUF_SIZE (64 * 1024) +#define DWC2_DATA_BUF_SIZE (CONFIG_USB_DWC2_BUFFER_SIZE * 1024) #define MAX_DEVICE 16 #define MAX_ENDPOINT 16
If we use hardware with very small RAM (let's consider just a couple of hundreds of kB but not megabytes) it is not super convenient to lose 64kB for statically allocated bufer which most probably won't be used as big as it is. Typically we'll have much shorter data packages to excahnge and in the worst case longer packets will be split on separate transactions. For those corner-cases user will be able to set his buffer size of choice via USB_DWC2_BUFFER_SIZE option in menuconfig. By default we'll use 64 kB as it was hard-coeded before so existing users shouldn't be affected at all. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Marek Vasut <marex@denx.de> --- drivers/usb/host/Kconfig | 12 ++++++++++++ drivers/usb/host/dwc2.c | 2 +- 2 files changed, 13 insertions(+), 1 deletion(-)