Re: [PATCH 2/8] usb: gadget: add anonymous definition in some struct for trace purpose
From: Linyu Yuan <hidden>
Date: 2023-09-15 01:56:57
Also in:
linux-usb
On 9/15/2023 9:51 AM, Alan Stern wrote:
On Fri, Sep 15, 2023 at 09:02:48AM +0800, Linyu Yuan wrote:quoted
On 9/14/2023 10:54 PM, Alan Stern wrote:quoted
You didn't include the version number in the Subject: line. Undoubtedly Greg's automatic error checker will warn you about this. Unless the version number is clearly marked for each patch, it's difficult for his programs to tell which email message contains the most recent version. On Thu, Sep 14, 2023 at 06:02:56PM +0800, Linyu Yuan wrote:quoted
Some UDC trace event will save usb udc information, but it use one int size buffer to save one bit information of usb udc, it is wast trace buffer. Add anonymous union which have one u32 member can be used by trace event during fast assign stage to save more entries with same trace ring buffer size. Signed-off-by: Linyu Yuan <redacted> ---And you didn't include the version change information here, below the "---" line. Apart from that, this is a _lot_ better than before! I don't know if Greg will think this change is worth merging, but at least now it's possible to read the code and understand what's going on.according Steven's comment, maybe will always save data in little endian at trace event fast assign stage. it will add definition of bit field back.Yes, that would be even better because you wouldn't have to change the definition of struct usb_gadget or struct usb_endpoint at all. The fast assign stage can simply do: __entry->dw1 = (g->sg_supported << 0) | (g->is_otg << 1) | ... and then you can easily access the individual bits in __entry. It wouldn't be as fast but it would still save a lot of space.
how about __entry->dw1 = cpu_to_le32(g->dw1) ?
Alan Stern