Re: [PATCH] tpm_tis: fix stall after iowrite*()s

2017-08-15 Thread Haris Okanovic
On 08/15/2017 01:11 AM, Alexander Stein wrote: On Monday 14 August 2017 17:53:47, Haris Okanovic wrote: --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -52,6 +52,22 @@ static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *da return container_of(data

Re: [PATCH] tpm_tis: fix stall after iowrite*()s

2017-08-14 Thread Alexander Stein
On Monday 14 August 2017 17:53:47, Haris Okanovic wrote: > --- a/drivers/char/tpm/tpm_tis.c > +++ b/drivers/char/tpm/tpm_tis.c > @@ -52,6 +52,22 @@ static inline struct tpm_tis_tcg_phy > *to_tpm_tis_tcg_phy(struct tpm_tis_data *da return container_of(data, > struct tpm_tis_tcg_phy, priv); > } > >

[PATCH] tpm_tis: fix stall after iowrite*()s

2017-08-14 Thread Haris Okanovic
ioread8() operations to TPM MMIO addresses can stall the cpu when immediately following a sequence of iowrite*()'s to the same region. For example, cyclitest measures ~400us latency spikes when a non-RT usermode application communicates with an SPI-based TPM chip (Intel Atom E3940 system, PREEMPT_