From: Corey Minyard <minyard@acm.org>
To: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-i2c@vger.kernel.org,
openipmi-developer@lists.sourceforge.net,
linux-kernel@vger.kernel.org,
Colin Ian King <colin.king@canonical.com>,
Vijay Khemka <vijaykhemka@fb.com>,
Asmaa Mnebhi <Asmaa@mellanox.com>
Subject: Re: [PATCH RFC 3/3] ipmi: remove open coded version of SMBus block write
Date: Wed, 13 Jan 2021 18:48:22 -0600 [thread overview]
Message-ID: <20210114004822.GY3348@minyard.net> (raw)
In-Reply-To: <20210112164130.47895-4-wsa+renesas@sang-engineering.com>
On Tue, Jan 12, 2021 at 05:41:29PM +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.
I asked the original authors of this about the change, and apparently is
results in a stack size warning. Arnd Bergmann ask for it to be changed
from what you are suggesting to what it currently is. See:
https://www.lkml.org/lkml/2019/6/19/440
So apparently this change will cause compile warnings due to the size of
struct i2c_client.
-corey
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
> drivers/char/ipmi/ipmb_dev_int.c | 21 ++++++++-------------
> 1 file changed, 8 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmb_dev_int.c b/drivers/char/ipmi/ipmb_dev_int.c
> index 382b28f1cf2f..10d89886e5f3 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 +160,16 @@ 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;
> + memcpy(&temp_client, ipmb_dev->client, sizeof(temp_client));
> + 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);
> -
> - return ret ? : count;
> + ret = i2c_smbus_write_block_data(&temp_client, netf_rq_lun, msg_len,
> + msg + SMBUS_MSG_IDX_OFFSET);
> + return ret < 0 ? ret : count;
> }
>
> static __poll_t ipmb_poll(struct file *file, poll_table *wait)
> --
> 2.29.2
>
next prev parent reply other threads:[~2021-01-14 1:46 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 16:41 [PATCH RFC 0/3] treewide: remove open coded SMBus block transfers Wolfram Sang
2021-01-12 16:41 ` [PATCH RFC 1/3] media: i2c: adv7842: remove open coded version of SMBus block write Wolfram Sang
2021-01-18 9:24 ` Hans Verkuil
2021-01-18 9:32 ` Wolfram Sang
2021-01-12 16:41 ` [PATCH RFC 2/3] media: i2c: adv7842: remove open coded version of SMBus block read Wolfram Sang
2021-01-12 16:44 ` Wolfram Sang
2021-01-12 19:41 ` Wolfram Sang
2021-01-18 9:22 ` Hans Verkuil
2021-01-18 9:33 ` Wolfram Sang
2021-01-12 16:41 ` [PATCH RFC 3/3] ipmi: remove open coded version of SMBus block write Wolfram Sang
2021-01-14 0:48 ` Corey Minyard [this message]
2021-01-14 14:04 ` Wolfram Sang
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