> On Mon, Jun 27, 2022 at 02:56:40AM +0000, Neal Liu wrote:
> > > On Fri, Jun 24, 2022 at 10:19:16AM +0800, Neal Liu wrote:
> > > > Add read TOC with format 1 to support CD-ROM emulation with
> > > > Windows OS.
> > > > This patch is tested on Windows OS Server 2019.
> > > >
> > > > Signed-off-by: Neal Liu <neal_liu@xxxxxxxxxxxxxx>
> > > > ---
> > > > drivers/usb/gadget/function/f_mass_storage.c | 5 +++--
> > > > 1 file changed, 3 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/usb/gadget/function/f_mass_storage.c
> > > > b/drivers/usb/gadget/function/f_mass_storage.c
> > > > index 3a77bca0ebe1..9edf76c22605 100644
> > > > --- a/drivers/usb/gadget/function/f_mass_storage.c
> > > > +++ b/drivers/usb/gadget/function/f_mass_storage.c
> > > > @@ -1209,7 +1209,8 @@ static int do_read_toc(struct fsg_common
> > > > *common, struct fsg_buffhd *bh)
> > > >
> > > > switch (format) {
> > > > case 0:
> > > > - /* Formatted TOC */
> > > > + case 1:
> > > > + /* Formatted TOC, Session info */
> > >
> > > This comment is a little misleading. 0 is formatted TOC, and 1 is
> > > multi-session info. The way you wrote it, it looks like the comment
> > > applies to both formats. Do it like this:
> > >
> > > case 0: /* Formatted TOC */
> > > case 1: /* Multi-session info */
> > >
> >
> > Okay, looks more clear. I'll fix it in next patch.
> >
> > > > len = 4 + 2*8; /* 4 byte header + 2 descriptors */
> > > > memset(buf, 0, len);
> > > > buf[1] = len - 2; /* TOC Length excludes length field */
> > >
> > > It looks like you ignored one of the problems I pointed out in my earlier
> email:
> > >
> > > > When format is 1, the driver is supposed to ignore the start_track
> > > > value. Your patch does not do this.
> > >
> > > Please fix this.
> > >
> >
> > Do you mean ignore the "start_track > 1" above?
>
> Yes, that's what I mean.
>
> > Do this check only for format 0? Or format 0 & 2?
>
> According to the MMC spec, the Track/Session Number is ignored for format 1.
> For format 0 it is valid as a Track Number, and for format 2 it is valid as a
> Session Number. Therefore it should be checked for formats 0 and 2 but not
> for format 1.
>
> Alan Stern
Got it. I'll fix this in next patch, thanks for pointing out.
