| Message ID | 20180221094804.21313-1-abrodkin@synopsys.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | Marek Vasut |
| Headers | show |
| Series | [U-Boot] usb: dwc2: Reduce data buffer size to 16kB | expand |
> -----Original Message----- > From: U-Boot [mailto:u-boot-bounces@lists.denx.de] On Behalf Of Alexey > Brodkin > Sent: Wednesday, February 21, 2018 3:18 PM > To: u-boot@lists.denx.de > Cc: Marek Vasut <marex@denx.de>; Alexey Brodkin > <Alexey.Brodkin@synopsys.com> > Subject: [U-Boot] [PATCH] usb: dwc2: Reduce data buffer size to 16kB > > 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 s/ excahnge /exchange Regards Calvin
On 02/21/2018 10:48 AM, 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. > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> > Cc: Marek Vasut <marex@denx.de> I think it does make sense to make this configurable with 64 kiB as default and tweak your platform to 16 kiB in it's defconfig. > --- > drivers/usb/host/dwc2.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c > index 0efe645044c5..20cd4a6d3d55 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 (16 * 1024) > > #define MAX_DEVICE 16 > #define MAX_ENDPOINT 16 >
diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c index 0efe645044c5..20cd4a6d3d55 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 (16 * 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. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Marek Vasut <marex@denx.de> --- drivers/usb/host/dwc2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)