Hi, On 1/8/24 07:20, Shin'ichiro Kawasaki wrote: > When PCI devices call p2sb_bar() during probe for sysfs PCI bus rescan, deadlock > happens due to double lock of pci_rescan_remove_lock [1]. The first patch in > this series addresses the deadlock. The second patch is a code improvement which > was pointed out during review for the first patch. > > [1] https://lore.kernel.org/linux-pci/6xb24fjmptxxn5js2fjrrddjae6twex5bjaftwqsuawuqqqydx@7cl3uik5ef6j/ > > The first patch of the v5 series was upstreamed to the kernel v6.7-rc8. However, > it caused IDE controller detection failure on an old platform [2] then the patch > was reverted at v6.7. The failure happened because the IDE controller had same > DEVFN as P2SB device. To avoid this failure, I added device class check per > suggestion by Lukas. If the device at P2SB DEVFN does not have the device class > expected for P2SB, avoid touching the device. > > [2] https://lore.kernel.org/platform-driver-x86/CABq1_vjfyp_B-f4LAL6pg394bP6nDFyvg110TOLHHb0x4aCPeg@xxxxxxxxxxxxxx/ > > I confirmed the patches fix the problem [1] on the kernel v6.7, using a system > with i2c_i801 device, building i2c_i801 module as both built-in and loadable. > Reviews and comments will be appreciated. > > Klara, > > I hesitated to add your Tested-by tag to the v6 patch, since I modified the code > slightly from the code you tested (I used pci_bus_read_config_word() instead of > pci_bus_read_config_dword() to avoid a shift operator). I hope you have time to > afford to test this series again. Thank you for your patch-series, I've applied this series to my review-hans branch: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans I will include this series in my next fixes pull-req to Linus for the current kernel development cycle. Note I have re-added Andy's and Ilpo's Reviewed-by for patch 1/2 since there is only one small change there. Regards, Hans > > > Changes from v5: > * Added device class check to avoid old IDE controller detection failure > > Changes from v4: > * Separated a hunk for pci_resource_n() as the second patch > * Reflected other review comments by Ilpo > > Changes from v3: > * Modified p2sb_valid_resource() to return boolean > > Changes from v2: > * Improved p2sb_scan_and_cache() and p2sb_scan_and_cache_devfn() > * Reflected other review comments by Andy > > Changes from v1: > * Reflected review comments by Andy > * Removed RFC prefix > > Changes from RFC v2: > * Reflected review comments on the list > > Changes from RFC v1: > * Fixed a build warning poitned out in llvm list by kernel test robot > > Shin'ichiro Kawasaki (2): > platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe > platform/x86: p2sb: Use pci_resource_n() in p2sb_read_bar0() > > drivers/platform/x86/p2sb.c | 183 +++++++++++++++++++++++++++--------- > 1 file changed, 141 insertions(+), 42 deletions(-) >
