linux-kernel - Re: [PATCH RESEND] ipmi: remove open coded version of SMBus block write

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Message-ID: <20210128123757.GW21462@minyard.net>
Date:   Thu, 28 Jan 2021 06:37:57 -0600
From:   Corey Minyard <cminyard@...sta.com>
To:     Wolfram Sang <wsa+renesas@...g-engineering.com>
Cc:     linux-i2c@...r.kernel.org, Asmaa Mnebhi <asmaa@...dia.com>,
        Corey Minyard <minyard@....org>,
        openipmi-developer@...ts.sourceforge.net,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH RESEND] ipmi: remove open coded version of SMBus block
 write

Looks good, do you want this in the IPMI tree or are you handling this
another way?

Thanks,

-corey

On Thu, Jan 28, 2021 at 09:55:43AM +0100, Wolfram Sang wrote:
> The block-write function of the core was not used because there was no
> client-struct to use. However, in this case it seems apropriate to use a
> temporary client struct. Because we are answering a request we recieved
> when being a client ourselves. So, convert the code to use a temporary
> client and use the block-write function of the I2C core.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@...g-engineering.com>
> Reviewed-by: Asmaa Mnebhi <asmaa@...dia.com>
> Acked-by: Corey Minyard <cminyard@...sta.com>
> ---
> 
> No change since V1, Only added tags given in private communication.
> 
>  drivers/char/ipmi/ipmb_dev_int.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/char/ipmi/ipmb_dev_int.c b/drivers/char/ipmi/ipmb_dev_int.c
> index 382b28f1cf2f..49b8f22fdcf0 100644
> --- a/drivers/char/ipmi/ipmb_dev_int.c
> +++ b/drivers/char/ipmi/ipmb_dev_int.c
> @@ -137,7 +137,7 @@ static ssize_t ipmb_write(struct file *file, const char __user *buf,
>  {
>  	struct ipmb_dev *ipmb_dev = to_ipmb_dev(file);
>  	u8 rq_sa, netf_rq_lun, msg_len;
> -	union i2c_smbus_data data;
> +	struct i2c_client *temp_client;
>  	u8 msg[MAX_MSG_LEN];
>  	ssize_t ret;
>  
> @@ -160,21 +160,21 @@ static ssize_t ipmb_write(struct file *file, const char __user *buf,
>  	}
>  
>  	/*
> -	 * subtract rq_sa and netf_rq_lun from the length of the msg passed to
> -	 * i2c_smbus_xfer
> +	 * subtract rq_sa and netf_rq_lun from the length of the msg. Fill the
> +	 * temporary client. Note that its use is an exception for IPMI.
>  	 */
>  	msg_len = msg[IPMB_MSG_LEN_IDX] - SMBUS_MSG_HEADER_LENGTH;
> -	if (msg_len > I2C_SMBUS_BLOCK_MAX)
> -		msg_len = I2C_SMBUS_BLOCK_MAX;
> +	temp_client = kmemdup(ipmb_dev->client, sizeof(*temp_client), GFP_KERNEL);
> +	if (!temp_client)
> +		return -ENOMEM;
> +
> +	temp_client->addr = rq_sa;
>  
> -	data.block[0] = msg_len;
> -	memcpy(&data.block[1], msg + SMBUS_MSG_IDX_OFFSET, msg_len);
> -	ret = i2c_smbus_xfer(ipmb_dev->client->adapter, rq_sa,
> -			     ipmb_dev->client->flags,
> -			     I2C_SMBUS_WRITE, netf_rq_lun,
> -			     I2C_SMBUS_BLOCK_DATA, &data);
> +	ret = i2c_smbus_write_block_data(temp_client, netf_rq_lun, msg_len,
> +					 msg + SMBUS_MSG_IDX_OFFSET);
> +	kfree(temp_client);
>  
> -	return ret ? : count;
> +	return ret < 0 ? ret : count;
>  }
>  
>  static __poll_t ipmb_poll(struct file *file, poll_table *wait)
> -- 
> 2.28.0
>