]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
tpm_tis: Disable interrupts on ThinkPad T490s
authorJerry Snitselaar <jsnitsel@redhat.com>
Thu, 15 Oct 2020 21:44:30 +0000 (14:44 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 18 Nov 2020 18:18:46 +0000 (19:18 +0100)
commitd3b4018b8eb32bb0d7341e7c1b4d10c3665fdb00
treec8970c603b3b4d7b14d9c42ecc11d0e419ed42a4
parentcb23120e8a7a569ba18631c38691aa38a9bd1e9b
tpm_tis: Disable interrupts on ThinkPad T490s

[ Upstream commit b154ce11ead925de6a94feb3b0317fafeefa0ebc ]

There is a misconfiguration in the bios of the gpio pin used for the
interrupt in the T490s. When interrupts are enabled in the tpm_tis
driver code this results in an interrupt storm. This was initially
reported when we attempted to enable the interrupt code in the tpm_tis
driver, which previously wasn't setting a flag to enable it. Due to
the reports of the interrupt storm that code was reverted and we went back
to polling instead of using interrupts. Now that we know the T490s problem
is a firmware issue, add code to check if the system is a T490s and
disable interrupts if that is the case. This will allow us to enable
interrupts for everyone else. If the user has a fixed bios they can
force the enabling of interrupts with tpm_tis.interrupts=1 on the
kernel command line.

Cc: Peter Huewe <peterhuewe@gmx.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/char/tpm/tpm_tis.c