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Date:   Thu, 22 Jul 2021 16:12:15 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Thomas Zimmermann <tzimmermann@suse.de>
Cc:     Xiaotian Feng <xtfeng@gmail.com>,
        kernel test robot <lkp@intel.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        stable@vger.kernel.org,
        "Michael J. Ruhl" <michael.j.ruhl@intel.com>,
        dri-devel@lists.freedesktop.org, Dave Airlie <airlied@redhat.com>
Subject: Re: [PATCH 5.12 237/242] drm/ast: Remove reference to struct
 drm_device.pdev
Message-ID: <YPl8v+FZ6PUl7XTl@kroah.com>
References: <20210715182551.731989182@linuxfoundation.org>
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 <YPVgtybrZLxe3XeW@kroah.com>
 <2ba3d853-f334-ba0e-3cdc-1e9a03f99b51@suse.de>
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On Mon, Jul 19, 2021 at 04:35:21PM +0200, Thomas Zimmermann wrote:
> hi
> 
> Am 19.07.21 um 13:23 schrieb Greg Kroah-Hartman:
> > On Mon, Jul 19, 2021 at 05:57:30PM +0800, Xiaotian Feng wrote:
> > > On Fri, Jul 16, 2021 at 5:13 AM Greg Kroah-Hartman
> > > <gregkh@linuxfoundation.org> wrote:
> > > > 
> > > > From: Thomas Zimmermann <tzimmermann@suse.de>
> > > > 
> > > > commit 0ecb51824e838372e01330752503ddf9c0430ef7 upstream.
> > > > 
> > > > Using struct drm_device.pdev is deprecated. Upcast with to_pci_dev()
> > > > from struct drm_device.dev to get the PCI device structure.
> > > > 
> > > > v9:
> > > >          * fix remaining pdev references
> > > > 
> > > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> > > > Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > > > Fixes: ba4e0339a6a3 ("drm/ast: Fixed CVE for DP501")
> > > > Cc: KuoHsiang Chou <kuohsiang_chou@aspeedtech.com>
> > > > Cc: kernel test robot <lkp@intel.com>
> > > > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > > > Cc: Dave Airlie <airlied@redhat.com>
> > > > Cc: dri-devel@lists.freedesktop.org
> > > > Link: https://patchwork.freedesktop.org/patch/msgid/20210429105101.25667-2-tzimmermann@suse.de
> > > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > > ---
> > > >   drivers/gpu/drm/ast/ast_main.c |    5 ++---
> > > >   1 file changed, 2 insertions(+), 3 deletions(-)
> > > > 
> > > > --- a/drivers/gpu/drm/ast/ast_main.c
> > > > +++ b/drivers/gpu/drm/ast/ast_main.c
> > > > @@ -411,7 +411,6 @@ struct ast_private *ast_device_create(co
> > > >                  return ast;
> > > >          dev = &ast->base;
> > > > 
> > > > -       dev->pdev = pdev;
> > > >          pci_set_drvdata(pdev, dev);
> > > > 
> > > >          ast->regs = pcim_iomap(pdev, 1, 0);
> > > > @@ -453,8 +452,8 @@ struct ast_private *ast_device_create(co
> > > > 
> > > >          /* map reserved buffer */
> > > >          ast->dp501_fw_buf = NULL;
> > > > -       if (dev->vram_mm->vram_size < pci_resource_len(dev->pdev, 0)) {
> > > > -               ast->dp501_fw_buf = pci_iomap_range(dev->pdev, 0, dev->vram_mm->vram_size, 0);
> > > > +       if (dev->vram_mm->vram_size < pci_resource_len(pdev, 0)) {
> > > > +               ast->dp501_fw_buf = pci_iomap_range(pdev, 0, dev->vram_mm->vram_size, 0);
> > > >                  if (!ast->dp501_fw_buf)
> > > >                          drm_info(dev, "failed to map reserved buffer!\n");
> > > >          }
> > > > 
> > > 
> > > Hi Greg,
> > > 
> > >       This backport is incomplete for 5.10 kernel,  kernel is panicked
> > > on RIP: ast_device_create+0x7d.  When I look into the crash code, I
> > > found
> > > 
> > > struct ast_private *ast_device_create(struct drm_driver *drv,
> > >                                        struct pci_dev *pdev,
> > >                                        unsigned long flags)
> > > {
> > > .......
> > >          dev->pdev = pdev;  // This is removed
> > >          pci_set_drvdata(pdev, dev);
> > > 
> > >          ast->regs = pcim_iomap(pdev, 1, 0);
> > >          if (!ast->regs)
> > >                  return ERR_PTR(-EIO);
> > > 
> > >          /*
> > >           * If we don't have IO space at all, use MMIO now and
> > >           * assume the chip has MMIO enabled by default (rev 0x20
> > >           * and higher).
> > >           */
> > >          if (!(pci_resource_flags(dev->pdev, 2) & IORESOURCE_IO)) { //
> > > dev->pdev is in used here.
> > >                  drm_info(dev, "platform has no IO space, trying MMIO\n");
> > >                  ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
> > >          }
> > > 
> > >          That's because commit 46fb883c3d0d8a823ef995ddb1f9b0817dea6882
> > > is not backported to 5.10 kernel.
> > 
> > So what should I do here?  Backport that commit (was was not called
> > out), or just revert this?
> 
> Best drop all these 'remove pdev' patches from stable. They are no bugfixes.

Which specific commits were they?

thanks,

greg k-h