Re: [PATCH] firmware: sysfb: Fix reference count of sysfb parent device

Hi

Am 28.06.24 um 20:54 schrieb Marek Olšák:

Hi Thomas,

FYI, this doesn't fix the issue of lightdm not being able to start for me.

Of course, that's expected. It's a different bug.

Best regards Thomas

Marek

Marek

On Tue, Jun 25, 2024 at 4:18 AM Thomas Zimmermann tzimmermann@suse.de wrote:

...

Retrieving the system framebuffer's parent device in sysfb_init() increments the parent device's reference count. Hence release the reference before leaving the init function.

Adding the sysfb platform device acquires and additional reference for the parent. This keeps the parent device around while the system framebuffer is in use.

Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Fixes: 9eac534db001 ("firmware/sysfb: Set firmware-framebuffer parent device") Cc: Thomas Zimmermann tzimmermann@suse.de Cc: Javier Martinez Canillas javierm@redhat.com Cc: Helge Deller deller@gmx.de Cc: Jani Nikula jani.nikula@intel.com Cc: Dan Carpenter dan.carpenter@linaro.org Cc: Arnd Bergmann arnd@arndb.de Cc: Sui Jingfeng suijingfeng@loongson.cn Cc: stable@vger.kernel.org # v6.9+

---

drivers/firmware/sysfb.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c index 880ffcb50088..dd274563deeb 100644 --- a/drivers/firmware/sysfb.c +++ b/drivers/firmware/sysfb.c @@ -101,8 +101,10 @@ static __init struct device *sysfb_parent_dev(const struct screen_info *si) if (IS_ERR(pdev)) { return ERR_CAST(pdev); } else if (pdev) {

•           if (!sysfb_pci_dev_is_enabled(pdev))
  

•           if (!sysfb_pci_dev_is_enabled(pdev)) {
  

•                   pci_dev_put(pdev);
                     return ERR_PTR(-ENODEV);
  

•           }
             return &pdev->dev;
     }
  
  

@@ -137,7 +139,7 @@ static __init int sysfb_init(void) if (compatible) { pd = sysfb_create_simplefb(si, &mode, parent); if (!IS_ERR(pd))

•                   goto unlock_mutex;
  

•                   goto put_device;
     }
  
     /* if the FB is incompatible, create a legacy framebuffer device */
  

@@ -155,7 +157,7 @@ static __init int sysfb_init(void) pd = platform_device_alloc(name, 0); if (!pd) { ret = -ENOMEM;

•           goto unlock_mutex;
  

•           goto put_device;
     }
  
     pd->dev.parent = parent;
  

@@ -170,9 +172,12 @@ static __init int sysfb_init(void) if (ret) goto err;

•   goto unlock_mutex;
  

•   goto put_device;
  

  err: platform_device_put(pd);

+put_device:

•   put_device(parent);
  

  unlock_mutex: mutex_unlock(&disable_lock); return ret;

-- 2.45.2