| Message ID | 20220301133210.1433609-1-sasha.neftin@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Anthony Nguyen |
| Headers | show |
| Series | [v1,1/1] igc: Fix infinite loop in release_swfw_sync | expand |
On 3/1/2022 15:32, Sasha Neftin wrote: > An infinite loop may occur if we fail to acquire the HW semaphore, > which is needed for resource release. > This will typically happen if the hardware is surprise-removed. > At this stage there is nothing to do, except log an error and quit. > > Suggested-by: Dima Ruinskiy<dima.ruinskiy@intel.com> > Signed-off-by: Sasha Neftin<sasha.neftin@intel.com> > --- > drivers/net/ethernet/intel/igc/igc_i225.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) Tested-by: Naama Meir <naamax.meir@linux.intel.com>
diff --git a/drivers/net/ethernet/intel/igc/igc_i225.c b/drivers/net/ethernet/intel/igc/igc_i225.c index 66ea566488d1..59d5c467ea6e 100644 --- a/drivers/net/ethernet/intel/igc/igc_i225.c +++ b/drivers/net/ethernet/intel/igc/igc_i225.c @@ -156,8 +156,15 @@ void igc_release_swfw_sync_i225(struct igc_hw *hw, u16 mask) { u32 swfw_sync; - while (igc_get_hw_semaphore_i225(hw)) - ; /* Empty */ + /* Releasing the resource requires first getting the HW semaphore. + * If we fail to get the semaphore, there is nothing we can do, + * except log an error and quit. We are not allowed to hang here + * indefinitely, as it may cause denial of service or system crash. + */ + if (igc_get_hw_semaphore_i225(hw)) { + hw_dbg("Failed to release SW_FW_SYNC.\n"); + return; + } swfw_sync = rd32(IGC_SW_FW_SYNC); swfw_sync &= ~mask;
An infinite loop may occur if we fail to acquire the HW semaphore, which is needed for resource release. This will typically happen if the hardware is surprise-removed. At this stage there is nothing to do, except log an error and quit. Suggested-by: Dima Ruinskiy <dima.ruinskiy@intel.com> Signed-off-by: Sasha Neftin <sasha.neftin@intel.com> --- drivers/net/ethernet/intel/igc/igc_i225.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)