Re: [PATCH v2] drm,fbdev: td043mtea1: Convert sprintf() family to sysfs_emit() family

[Zhijian Li (Fujitsu)]

On 19/03/2024 16:07, Neil Armstrong wrote:
> Hi,
> 
> On 19/03/2024 04:55, Li Zhijian wrote:
>> Per filesystems/sysfs.rst, show() should only use sysfs_emit()
>> or sysfs_emit_at() when formatting the value to be returned to user space.
>>
>> coccinelle complains that there are still a couple of functions that use
>> snprintf(). Convert them to sysfs_emit().
>>
>> sprintf() and scnprintf() will be converted as well if they have.
>>
>> Generally, this patch is generated by
>> make coccicheck M=<path/to/file> MODE=patch \
>> COCCI=scripts/coccinelle/api/device_attr_show.cocci
>>
>> No functional change intended
> 
> Please split patches in 2, while the driver targets the same hw, they
> are not under the same subsystems.

Got it, i will do that soon.

Thanks
Zhijian

> 
> Neil
> 
>>
>> CC: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
>> CC: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
>> CC: Sam Ravnborg <sam@xxxxxxxxxxxx>
>> CC: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
>> CC: Maxime Ripard <mripard@xxxxxxxxxx>
>> CC: Thomas Zimmermann <tzimmermann@xxxxxxx>
>> CC: David Airlie <airlied@xxxxxxxxx>
>> CC: Daniel Vetter <daniel@xxxxxxxx>
>> CC: Helge Deller <deller@xxxxxx>
>> CC: linux-omap@xxxxxxxxxxxxxxx
>> CC: linux-fbdev@xxxxxxxxxxxxxxx
>> CC: dri-devel@xxxxxxxxxxxxxxxxxxxxx
>> Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
>> ---
>> V2:
>>     Fix missing '+' before '=' in drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
>>
>> This is a part of the work "Fix coccicheck device_attr_show warnings"[1]
>> Split them per subsystem so that the maintainer can review it easily
>> [1] https://lore.kernel.org/lkml/20240116041129.3937800-1-lizhijian@xxxxxxxxxxx/
>> ---
>>   drivers/gpu/drm/panel/panel-tpo-td043mtea1.c        | 13 ++++---------
>>   .../omap2/omapfb/displays/panel-tpo-td043mtea1.c    | 12 ++++--------
>>   2 files changed, 8 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c b/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
>> index cf4609bb9b1d..0983fe47eb5a 100644
>> --- a/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
>> +++ b/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
>> @@ -242,16 +242,11 @@ static ssize_t gamma_show(struct device *dev, struct device_attribute *attr,
>>       struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
>>       ssize_t len = 0;
>>       unsigned int i;
>> -    int ret;
>> -    for (i = 0; i < ARRAY_SIZE(lcd->gamma); i++) {
>> -        ret = snprintf(buf + len, PAGE_SIZE - len, "%u ",
>> -                   lcd->gamma[i]);
>> -        if (ret < 0)
>> -            return ret;
>> -        len += ret;
>> -    }
>> -    buf[len - 1] = '\n';
>> +    for (i = 0; i < ARRAY_SIZE(lcd->gamma); i++)
>> +        len += sysfs_emit_at(buf, len, "%u ", lcd->gamma[i]);
>> +    if (len)
>> +        buf[len - 1] = '\n';
>>       return len;
>>   }
>> diff --git a/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c b/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
>> index 477789cff8e0..3624452e1dd0 100644
>> --- a/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
>> +++ b/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
>> @@ -228,14 +228,10 @@ static ssize_t tpo_td043_gamma_show(struct device *dev,
>>       int ret;
>>       int i;
>> -    for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++) {
>> -        ret = snprintf(buf + len, PAGE_SIZE - len, "%u ",
>> -                ddata->gamma[i]);
>> -        if (ret < 0)
>> -            return ret;
>> -        len += ret;
>> -    }
>> -    buf[len - 1] = '\n';
>> +    for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++)
>> +        len += sysfs_emit_at(buf, len, "%u ", ddata->gamma[i]);
>> +    if (len)
>> +        buf[len - 1] = '\n';
>>       return len;
>>   }
>