On Mon, Jan 16, 2017 at 11:33:18AM +0200, Jarkko Sakkinen wrote: > On Fri, Jan 13, 2017 at 04:42:30PM -0800, Andrey Pronin wrote: > > On Fri, Jan 13, 2017 at 05:28:57PM -0700, Jason Gunthorpe wrote: > > > On Fri, Jan 13, 2017 at 04:09:54PM -0800, Andrey Pronin wrote: > > > > Resetting TPM while processing a command may lead to issues > > > > on the next boot. Ensure that we don't have any ongoing > > > > commands, and that no further commands can be sent to the chip > > > > by unregistering the device in the shutdown handler. > > > > tpm_chip_unregister() waits for the completion of an ongoing > > > > command, if any, and then clears out chip->ops and unregisters > > > > sysfs entities. > > > > > > Unregistering in a shutdown handler seems very strange, it also waits > > > for userspace things, so I wonder if it could be problematic? > > > > > > Maybe just use > > > > > > down_write(&chip->ops_sem); > > > chip->ops = NULL; > > > up_write(&chip->ops_sem); > > > > > > In the shutdown handler? > > > > down_write(&chip->ops_sem) would still wait for completing the initiated > > writes, since tpm_write() in tpm-dev.c calls tpm_try_get_ops(). > > Also, tpm-sysfs.c calls chip->ops directly, so sysfs should be > > unregistered first. > > Why don't you fix the tpm-sysfs issue but rather misusing > tpm_chip_unregister?
Ignore this. I wasn't following this thread properly. Only now had time read carefully through the discussion. /Jarkko ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ tpmdd-devel mailing list tpmdd-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
