From: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx> commit 3c8604691d2acc7b7d4795d9695070de9eaa5828 upstream. While diag reset is in progress there is short duration where all access to controller's PCI config space from the host needs to be blocked. This is due to a hardware limitation of the IOC controllers. Block all access to controller's config space from userland applications by calling pci_cfg_access_lock() while diag reset is in progress and unlocking it again after the controller comes back to ready state. Link: https://lore.kernel.org/r/20210330105137.20728-1-sreekanth.reddy@xxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx #v5.4.108+ Signed-off-by: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/mpt3sas/mpt3sas_base.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -6572,6 +6572,8 @@ _base_diag_reset(struct MPT3SAS_ADAPTER ioc_info(ioc, "sending diag reset !!\n"); + pci_cfg_access_lock(ioc->pdev); + drsprintk(ioc, ioc_info(ioc, "clear interrupts\n")); count = 0; @@ -6653,10 +6655,12 @@ _base_diag_reset(struct MPT3SAS_ADAPTER goto out; } + pci_cfg_access_unlock(ioc->pdev); ioc_info(ioc, "diag reset: SUCCESS\n"); return 0; out: + pci_cfg_access_unlock(ioc->pdev); ioc_err(ioc, "diag reset: FAILED\n"); return -EFAULT; }
