Forwarded Message
Subject: [PATCH] [RFC] tpm_tis: tpm_tcg_flush() after iowrite*()s
Date: Fri, 4 Aug 2017 16:56:51 -0500
From: Haris Okanovic
To: linux-rt-us...@vger.kernel.org, linux-ker...@vger.kernel.org
CC: haris.okano...@ni.com, haris...@gmail.com, julia.cartwri...@ni.com
that follows.
The enclosed change appears to fix this issue: read the TPM chip's
access register (status code) after every iowrite*() operation to
amortize the cost of flushing data to chip across multiple instructions.
Signed-off-by: Haris Okanovic
---
https://patchwork.kernel.org/patch/9882
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
that follows.
The enclosed change appears to fix this issue: read the TPM chip's
access register (status code) after every iowrite*() operation to
amortize the cost of flushing data to chip across multiple instructions.
Signed-off-by: Haris Okanovic
---
[PATCH v2] Add tpm_tis_flush() fun
Neither wmb() nor mb() have any effect when substituted for
ioread8(iobase + TPM_ACCESS(0)) in tpm_tis_flush(). I still see 300 -
400 us spikes in cyclictest invoking my TPM chip's RNG.
-- Haris
On 08/17/2017 12:17 PM, Jason Gunthorpe wrote:
On Thu, Aug 17, 2017 at 12:38:07PM +0200, Sebastia
