Messages in this thread | | | Subject | Re: [PATCH] tpm_tis: fix stall after iowrite*()s | From | Haris Okanovic <> | Date | Tue, 15 Aug 2017 15:10:33 -0500 |
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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, >> struct tpm_tis_tcg_phy, priv); >> } >> >> +static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr) >> +{ >> + iowrite8(b, iobase + addr); >> +#ifdef CONFIG_PREEMPT_RT_FULL >> + ioread8(iobase + TPM_ACCESS(0)); >> +#endif >> +} > > Maybe add some comment why an iorad8 is actually requried after each write on > RT. Currently it is rather obvious why this additional read is necessary. But > is this still the case in a year? >
Sure. I re-added the tpm_tis_flush() function with comments to explain what's going. Calling it from tpm_tis_iowrite8() and tpm_tis_iowrite32().
Will post a PATCH v2 shortly.
>> +static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr) >> +{ >> + iowrite32(b, iobase + addr); >> +#ifdef CONFIG_PREEMPT_RT_FULL >> + ioread8(iobase + TPM_ACCESS(0)); >> +#endif >> +} > > Same applies here. Or add a comment above both functions describing their > purpose. > > Just my 2 cents > > Best regards, > Alexander >
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