On Fri, Aug 30, 2019 at 06:56:39PM +0900, Seunghun Han wrote: > I got an AMD system which had a Ryzen Threadripper 1950X and MSI > mainboard, and I had a problem with AMD's fTPM. My machine showed an error > message below, and the fTPM didn't work because of it. > > [ 5.732084] tpm_crb MSFT0101:00: can't request region for resource > [mem 0x79b4f000-0x79b4ffff] > [ 5.732089] tpm_crb: probe of MSFT0101:00 failed with error -16 > > When I saw the iomem, I found two fTPM regions were in the ACPI NVS area. > The regions are below. > > 79a39000-79b6afff : ACPI Non-volatile Storage > 79b4b000-79b4bfff : MSFT0101:00 > 79b4f000-79b4ffff : MSFT0101:00 > > After analyzing this issue, I found that crb_map_io() function called > devm_ioremap_resource() and it failed. The ACPI NVS didn't allow the TPM > CRB driver to assign a resource in it because a busy bit was set to > the ACPI NVS area. > > To support AMD's fTPM, I added a function to check intersects between > the TPM region and ACPI NVS before it mapped the region. If some > intersects are detected, the function just calls devm_ioremap() for > a workaround. If there is no intersect, it calls devm_ioremap_resource(). > > Signed-off-by: Seunghun Han <kkamagui@xxxxxxxxx> > --- > drivers/char/tpm/tpm_crb.c | 25 +++++++++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) This still seems to result in two drivers controlling the same memory. Does this create bugs and races during resume? Jason
