tree 046ef656112c1ee650518a0bbeab43adf1522b93
parent 5975c725dfd6f7d36f493ab1453fbdbd35c1f0e3
author Rajiv Andrade <srajiv@linux.vnet.ibm.com> 1252613375 -0300
committer James Morris <jmorris@namei.org> 1257113344 +1100

tpm_tis: TPM_STS_DATA_EXPECT workaround

Some newer Lenovo models are shipped with a TPM that doesn't seem to set the TPM_STS_DATA_EXPECT status bit
when sending it a burst of data, so the code understands it as a failure and doesn't proceed sending the chip
the intended data. In this patch we bypass this bit check in case the itpm module parameter was set.

This patch is based on Andy Isaacson's one:

http://marc.info/?l=linux-kernel&m=124650185023495&w=2

It was heavily discussed how should we deal with identifying the chip in kernel space, but the required
patch to do so was NACK'd:

http://marc.info/?l=linux-kernel&m=124650186423711&w=2

This way we let the user choose using this workaround or not based on his
observations on this code behavior when trying to use the TPM.

Fixed a checkpatch issue present on the previous patch, thanks to Daniel Walker.

Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Tested-by: Seiji Munetoh <seiji.munetoh@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>