From: "Guilherme G. Piccoli" <gpicc...@linux.vnet.ibm.com> Date: Wed, 31 Aug 2016 12:11:57 -0300
> When PCI error is detected, in some architectures (like PowerPC) a slot > reset is performed - the driver's error handlers are in charge of "disable" > device before the reset, and re-enable it after a successful slot reset. > > There are two cases though that another path is taken on the code: if the > slot reset is not successful or if too many errors already happened in the > specific adapter (meaning that possibly the device is experiencing a HW > failure that slot reset is not able to solve), the core PCI error mechanism > (called EEH in PowerPC) will remove the adapter from the system, since it > will consider this as a permanent failure on device. In this case, a path > is taken that leads to bnx2x_chip_cleanup() calling bnx2x_reset_hw(), which > then tries to perform a HW reset on chip. This reset won't succeed since > the HW is in a fault state, which can be seen by multiple messages on > kernel log like below: > > bnx2x: [bnx2x_issue_dmae_with_comp:552(eth1)]DMAE timeout! > bnx2x: [bnx2x_write_dmae:600(eth1)]DMAE returned failure -1 > > After some time, the PCI error mechanism gives up on waiting the driver's > correct removal procedure and forcibly remove the adapter from the system. > We can see soft lockup while core PCI error mechanism is waiting for driver > to accomplish the right removal process. > > This patch adds a verification to avoid a chip reset whenever the function > is in PCI error state - since this case is only reached when we have a > device being removed because of a permanent failure, the HW chip reset is > not expected to work fine neither is necessary. > > Also, as a minor improvement in error path, we avoid the MCP information dump > in case of non-recoverable PCI error (when adapter is about to be removed), > since it will certainly fail. > > Reported-by: Harsha Thyagaraja <hathy...@in.ibm.com> > Signed-off-by: Guilherme G. Piccoli <gpicc...@linux.vnet.ibm.com> > --- > v2: Removed the unlikely attribute on bnx2x_fw_dump_lvl() if block. Applied, thanks.
