On May 10, 2024 / 21:22, Klara Modin wrote: > On 2024-05-10 16:50, Andy Shevchenko wrote: > > On Thu, May 09, 2024 at 07:04:32PM +0200, Lukas Wunner wrote: > > > [cc += Shin'ichiro, Klara, Andy, Danil] > > > > Thank you! > > > > > On Thu, May 09, 2024 at 04:49:34PM +0000, bcfradella@xxxxxxxxx wrote: > > > > From: Ben Fradella <bfradell@xxxxxxxxxx> > > > > > > > > The P2SB could get an invalid BAR from the BIOS, and that won't be fixed > > > > up until pcibios_assign_resources(), which is an fs_initcall(). > > > > > > > > - Move p2sb_fs_init() to an fs_initcall_sync(). This is still early > > > > enough to avoid a race with any dependent drivers. > > > > > > > > - Add a check for IORESOURCE_UNSET in p2sb_valid_resource() to catch > > > > unset BARs going forward. > > > > > > > > - Return error values from p2sb_fs_init() so that the 'initcall_debug' > > > > cmdline arg provides useful data. > > > > ... > > > > > > /* > > > > - * pci_rescan_remove_lock to avoid access to unhidden P2SB devices can > > > > - * not be locked in sysfs pci bus rescan path because of deadlock. To > > > > - * avoid the deadlock, access to P2SB devices with the lock at an early > > > > - * step in kernel initialization and cache required resources. This > > > > - * should happen after subsys_initcall which initializes PCI subsystem > > > > - * and before device_initcall which requires P2SB resources. > > > > + * pci_rescan_remove_lock() can not be locked in sysfs pci bus rescan path > > > > PCI bus > > > > > > + * because of deadlock. To avoid the deadlock, access P2SB devices with the lock > > > > + * at an early step in kernel initialization and cache required resources. > > > > + * > > > > + * We want to run as early as possible. If the P2SB was assigned a bad BAR, > > > > + * we'll need to wait on pcibios_assign_resources() to fix it. So, our list of > > > > + * initcall dependencies looks something like this: > > > > + * > > > > + * ... > > > > + * subsys_initcall (pci_subsys_init) > > > > + * fs_initcall (pcibios_assign_resources) > > > > */ > > > > This makes sense to me > > Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > > > I assume others will conduct the proper review and testing. > > > > This patch did not introduce any new issues on my previously problematic > system. > > Tested-by: Klara Modin <klarasmodin@xxxxxxxxx> The changes look reasonable and good to me. I also confirmed that the patch does not affect on my use case using two my test machines. Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
