From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Wolfram Sang <wsa@the-dreams.de>,
linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org
Subject: Re: [PATCH] i2c: i2c-core: do not use bus internal data
Date: Mon, 07 Mar 2016 22:47:55 +0530 [thread overview]
Message-ID: <56DDB7C3.50307@gmail.com> (raw)
In-Reply-To: <20160307165733.GA20093@kroah.com>
On Monday 07 March 2016 10:27 PM, Greg KH wrote:
> On Mon, Mar 07, 2016 at 05:19:17PM +0530, Sudip Mukherjee wrote:
>> The variable p is a data structure which is used by the driver core
>> internally and it is not expected that busses will be directly accessing
>> these driver core internal only data.
>>
>> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
>> ---
>>
>> Reference of Greg's comment about it at:
>> https://lkml.org/lkml/2016/3/5/171
>>
>> drivers/i2c/i2c-core.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
>> index 2949ab3..2f31fb5 100644
>> --- a/drivers/i2c/i2c-core.c
>> +++ b/drivers/i2c/i2c-core.c
>> @@ -73,6 +73,7 @@ static struct device_type i2c_client_type;
>> static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
>>
>> static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
>> +static bool is_registered;
>>
>> void i2c_transfer_trace_reg(void)
>> {
>> @@ -1529,7 +1530,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
>> int res = 0;
>>
>> /* Can't register until after driver model init */
>> - if (unlikely(WARN_ON(!i2c_bus_type.p))) {
>> + if (unlikely(WARN_ON(!is_registered))) {
>> res = -EAGAIN;
>> goto out_list;
>> }
>
> Minor nit, likely/unlikely should only be used on very "hot paths" where
> the difference if it is not included can be measured. the "register a
> device" path is not "hot" at all.
I can submit a patch afterwards to remove the "unlikely" if that is ok
with Wolfram.
regards
sudip
next prev parent reply other threads:[~2016-03-07 17:18 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-07 11:49 [PATCH] i2c: i2c-core: do not use bus internal data Sudip Mukherjee
2016-03-07 16:57 ` Greg KH
2016-03-07 17:17 ` Sudip Mukherjee [this message]
2016-03-12 15:14 ` Wolfram Sang
2016-03-14 9:18 ` Thierry Reding
2016-03-14 9:27 ` Thierry Reding
2016-03-14 12:15 ` Sudeep Holla
2016-03-14 9:28 ` Wolfram Sang
2016-03-14 9:39 ` Thierry Reding
2016-03-14 14:25 ` Sudip Mukherjee
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