Linux-FPGA Archive mirror
 help / color / mirror / Atom feed

From: David Gideon <gideonda32@gmail.com>
To: yilun.xu@linux.intel.com, linux-fpga@vger.kernel.org
Subject: Re: info->header_size always 0, breaks fpga-zynq.c driver
Date: Thu, 18 Apr 2024 15:00:27 +1000	[thread overview]
Message-ID: <CAOLMD=wxmkRti3ny3kDz=hzZfSZeZn2_mdXhqGGPFO+7vPDEsw@mail.gmail.com> (raw)
In-Reply-To: <Zheim/iQP31H1pMh@yilunxu-OptiPlex-7050>

Thanks Yilun,

It looks like I'm using a mainline 6.1.55 kernel, but with Xilinx
patches over it.

One of those Xilinx kernel patches introduces loading firmware images
via the sysfs, and one of those functions calls
fpga_mgr_firmware_load() directly,
without first setting info->header_size (as fpga_mgr_load does).

I guess I'll shoot a message to the Xilinx guys.

Thanks!
-DG

On Thu, Apr 11, 2024 at 6:48 PM Xu Yilun <yilun.xu@linux.intel.com> wrote:
>
> On Thu, Apr 11, 2024 at 02:16:24PM +1000, David Gideon wrote:
> > Hi Everyone,
> >
> > Our Xilinx FPGA driver (zynq-fpga.c) is no longer compatible with
> > fpga-mgr.c and barfs with:
> >
> >       "Invalid bitstream, could not find a sync word. Bitstream must
> > be a byte swapped .bin file"
> >
> > It seems to come from here (inside fpga_mgr_write_init_buf()):
> >       size_t header_size = info->header_size;
> >
> > It uses header_size to decide whether or not to call
> > fpga_mgr_write_init() with a NULL buffer and a 0 size, or use a real
> > buffer and real size, like this:
> >
> >     if (header_size > count)
> >         ret = -EINVAL;
> >     else if (!header_size)
> >         ret = fpga_mgr_write_init(mgr, info, NULL, 0);
> >     else
> >         ret = fpga_mgr_write_init(mgr, info, buf, count);
> >
> > The trouble is, that if I follow my code path, info->header_size isn't
> > set by anyone.  So it's **ALWAYS** zero.  But the value **should** be
>
> From your link below, I see info->header_size is set here:
>
> @@ -404,6 +571,8 @@ static int fpga_mgr_firmware_load(struct fpga_manager *mgr,
>   */
>  int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info)
>  {
> +       info->header_size = mgr->mops->initial_header_size;
> +
>         if (info->sgt)
>                 return fpga_mgr_buf_load_sg(mgr, info, info->sgt);
>
> Thanks,
> Yilun
>
> > 128:
> >
> >     static const struct fpga_manager_ops zynq_fpga_ops = {
> >          .initial_header_size = 128,
> >         ...
> >     };
> >
> > The issue seems to have been introduced as part of commit 3cc624beba
> > which I have linked to here:
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/fpga/fpga-mgr.c?id=3cc624beba6310a8a534fb00841f22445a200d54
> >
> >
> > What I find really interesting is that the original mailing list patch
> > submission didn't have this bug, and would have worked for us:
> >
> >     + if (info->header_size)
> >         + header_size = info->header_size;
> >     + else
> >         + header_size = mgr->mops->initial_header_size;
> >
> > Could this be a viable way to ensure that the FPGA manager driver is
> > compatible with the zynq-fpga.c driver again?
> >
> >
> > - DG
> >

     prev parent reply	other threads:[~2024-04-18  5:09 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-11  4:16 info->header_size always 0, breaks fpga-zynq.c driver David Gideon
2024-04-11  8:43 ` Xu Yilun
2024-04-18  5:00   ` David Gideon [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAOLMD=wxmkRti3ny3kDz=hzZfSZeZn2_mdXhqGGPFO+7vPDEsw@mail.gmail.com' \
    --to=gideonda32@gmail.com \
    --cc=linux-fpga@vger.kernel.org \
    --cc=yilun.xu@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).