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Message-ID: <60218a3b-9b56-d9c1-a0f4-97c171a050ba@linux.intel.com>
Date:   Thu, 28 Apr 2022 16:07:47 +0300
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Subject: Re: [PATCH] i2c: designware: Modify timing parameters for amdpsp
 mailbox
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To:     Jan Dabros <jsd@semihalf.com>, linux-kernel@vger.kernel.org,
        linux-i2c@vger.kernel.org, andriy.shevchenko@linux.intel.com
Cc:     mika.westerberg@linux.intel.com, rrangel@chromium.org,
        Nimesh.Easow@amd.com, upstream@semihalf.com
References: <20220428122651.208575-1-jsd@semihalf.com>
From:   Jarkko Nikula <jarkko.nikula@linux.intel.com>
In-Reply-To: <20220428122651.208575-1-jsd@semihalf.com>
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On 4/28/22 15:26, Jan Dabros wrote:
> Adjust retry period and timeout values for x86-PSP mailbox based on the
> typical I2C traffic generated by PSP. In order to limit the possibility
> of timeouts, x86 should reduce the interval between retries as well as
> increase overall time after which it gives up.
> 
> Signed-off-by: Jan Dabros <jsd@semihalf.com>
> ---
>   drivers/i2c/busses/i2c-designware-amdpsp.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-amdpsp.c b/drivers/i2c/busses/i2c-designware-amdpsp.c
> index 9b37f2b95abc..b624356c945f 100644
> --- a/drivers/i2c/busses/i2c-designware-amdpsp.c
> +++ b/drivers/i2c/busses/i2c-designware-amdpsp.c
> @@ -16,8 +16,8 @@
>   #define PSP_CMD_TIMEOUT_US	(500 * USEC_PER_MSEC)
>   
>   #define PSP_I2C_REQ_BUS_CMD		0x64
> -#define PSP_I2C_REQ_RETRY_CNT		10
> -#define PSP_I2C_REQ_RETRY_DELAY_US	(50 * USEC_PER_MSEC)
> +#define PSP_I2C_REQ_RETRY_CNT		400
> +#define PSP_I2C_REQ_RETRY_DELAY_US	(25 * USEC_PER_MSEC)
>   #define PSP_I2C_REQ_STS_OK		0x0
>   #define PSP_I2C_REQ_STS_BUS_BUSY	0x1
>   #define PSP_I2C_REQ_STS_INV_PARAM	0x3

Out of curiosity, can it be up to 400 * 25 ms = 10 s?

Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>