lkml.org 
[lkml]   [2017]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] tpm_tis: fix stall after iowrite*()s
From
Date


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
>

\
 
 \ /
  Last update: 2017-08-15 22:11    [W:0.164 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site