On Tue, Sep 12, 2023 at 06:44:46PM +0800, Linyu Yuan wrote:
> Some UDC trace event will save usb gadget information, but it use one int
> size buffer to save one bit information of usb gadget, so 19 int buffers
> needed to save 19 bit fields which is not good.
>
> Add one anonymous union which have one u32 member 'dw1' to struct
> 'usb_gadget', it inlclude all 19 bits and can be used by trace event
> during fast assign stage to save more entries with same trace ring buffer
> size.
>
> Also move all original 19 bit fields into one anonymous struct which
> inside struct 'usb_gadget'.
>
> In order to allow trace event output stage access the bit from saved u32
> 'dw1', add following macro,
> define USB_GADGET_BITFIELD(n, name) \
> ({\
> union {\
> struct {\
> u32 sg_supported:1;\
> u32 is_otg:1;\
> u32 is_a_peripheral:1;\
> u32 b_hnp_enable:1;\
> u32 a_hnp_support:1;\
> u32 a_alt_hnp_support:1;\
> u32 hnp_polling_support:1;\
> u32 host_request_flag:1;\
> u32 quirk_ep_out_aligned_size:1;\
> u32 quirk_altset_not_supp:1;\
> u32 quirk_stall_not_supp:1;\
> u32 quirk_zlp_not_supp:1;\
> u32 quirk_avoids_skb_reserve:1;\
> u32 is_selfpowered:1;\
> u32 deactivated:1;\
> u32 connected:1;\
> u32 lpm_capable:1;\
> u32 wakeup_capable:1;\
> u32 wakeup_armed:1;\
> } __packed;\
> u32 dw1;\
> } __aligned(4) __g_u_##name;\
> u32 __g_##name; \
> BUILD_BUG_ON(sizeof(__g_u_##name) != 4);\
> __g_u_##name.dw1 = (n); __g_##name = __g_u_##name.name;\
> __g_##name; })
>
> define USB_GADGET_SG_SUPPORTED(n) USB_GADGET_BITFIELD((n), sg_supported)
> ...
> change to use this kind of macro for all related trace files later.
This macro usage is a real mess. Can't you find a better way to do it?
For instance, in the code that parses the trace buffer, define a
temporary usb_gadget structure and copy the dw1 field from the trace
buffer to the temporary structure. Then you can access the fields in
that structure directly by their original names, with no macros.
Alan Stern
