Re: [PATCH v8 1/1] usb: cdns3: allocate TX FIFO size according to composite EP number

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Apr 27, 2022 at 12:03:22PM -0500, Zhi Li wrote:
> On Wed, Apr 27, 2022 at 11:57 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Wed, Apr 27, 2022 at 11:35:25AM -0500, Frank Li wrote:
> > > Some devices have USB compositions which may require multiple endpoints.
> > > To get better performance, need bigger CDNS3_EP_BUF_SIZE.
> > >
> > > But bigger CDNS3_EP_BUF_SIZE may exceed total hardware FIFO size when
> > > multiple endpoints.
> > >
> > > By introducing the check_config() callback, calculate CDNS3_EP_BUF_SIZE.
> > >
> > > Move CDNS3_EP_BUF_SIZE into cnds3_device: ep_buf_size
> > > Combine CDNS3_EP_ISO_SS_BURST and CDNS3_EP_ISO_HS_MULT into
> > > ecnds3_device:ep_iso_burst
> > >
> > > Using a simple algorithm to calculate ep_buf_size.
> > > ep_buf_size = ep_iso_burst = (onchip_buffers - 2k) / (number of IN EP +
> > > 1).
> > >
> > > Test at 8qxp:
> > >
> > >       Gadget                  ep_buf_size
> > >
> > >       RNDIS:                          5
> > >       RNDIS+ACM:                      3
> > >       Mass Storage + NCM + ACM        2
> > >
> > > Previous CDNS3_EP_BUF_SIZE is 4, RNDIS + ACM will be failure because
> > > exceed FIFO memory.
> > >
> > > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > > ---
> > > Change from v1 to v2:
> > >  Add safe check for mult, buffering and maxburst
> >
> > that's nice, but this is v8, not v2?
> 
> Sorry, It should be v2. I made a mistake with the title.

Ok, the next version needs to be 9 to keep everything from getting
really confused.

thanks,

greg k-h