| Message ID | 20200517190139.740249-7-sam@ravnborg.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | backlight updates | expand |
On Sun, May 17, 2020 at 09:01:29PM +0200, Sam Ravnborg wrote: > Improve the documentation for backlight_device and > adapt it to kernel-doc style. > > Signed-off-by: Sam Ravnborg <sam@ravnborg.org> > Cc: Lee Jones <lee.jones@linaro.org> > Cc: Daniel Thompson <daniel.thompson@linaro.org> > Cc: Jingoo Han <jingoohan1@gmail.com> > --- > include/linux/backlight.h | 81 ++++++++++++++++++++++++++++----------- > 1 file changed, 58 insertions(+), 23 deletions(-) > > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index 7f9cef299d6e..e2d72936bf05 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -14,21 +14,6 @@ > #include <linux/mutex.h> > #include <linux/notifier.h> > > -/* Notes on locking: > - * > - * backlight_device->ops_lock is an internal backlight lock protecting the > - * ops pointer and no code outside the core should need to touch it. > - * > - * Access to update_status() is serialised by the update_lock mutex since > - * most drivers seem to need this and historically get it wrong. > - * > - * Most drivers don't need locking on their get_brightness() method. > - * If yours does, you need to implement it in the driver. You can use the > - * update_lock mutex if appropriate. > - * > - * Any other use of the locks below is probably wrong. > - */ > - > enum backlight_update_reason { > BACKLIGHT_UPDATE_HOTKEY, > BACKLIGHT_UPDATE_SYSFS, > @@ -221,30 +206,80 @@ struct backlight_properties { > enum backlight_scale scale; > }; > > +/** > + * struct backlight_device - backlight device data > + * > + * This structure holds all data required by a backlight device. > + */ > struct backlight_device { > - /* Backlight properties */ > + /** > + * @props: > + * As last patch. Why no brief descriptions? > + * Backlight properties > + */ > struct backlight_properties props; > > - /* Serialise access to update_status method */ > + /** > + * @update_lock: > + * > + * update_lock is an internal backlight lock that serialise access > + * to the update_status() method. The iupdate_lock mutex shall not be used > + * by backlight drivers. In addition to the typo this directly contradicts the advice in the original "Notes on locking". A change this dramatic needs to be fully explaining in the patch description. Daniel. > + */ > struct mutex update_lock; > > - /* This protects the 'ops' field. If 'ops' is NULL, the driver that > - registered this device has been unloaded, and if class_get_devdata() > - points to something in the body of that driver, it is also invalid. */ > + /** > + * @ops_lock: > + * > + * ops_lock is an internal backlight lock that protects the ops pointer > + * and is used around all accesses to ops and when the operations are > + * invoked. The mutex shall not be used by backlight drivers. > + */ > struct mutex ops_lock; > + > + /** > + * @ops: > + * > + * Pointer to the backlight operations. If ops is NULL, the driver that > + * registered this device has been unloaded, and if class_get_devdata() > + * points to something in the body of that driver, it is also invalid. > + */ > const struct backlight_ops *ops; > > - /* The framebuffer notifier block */ > + /** > + * @fb_notif: > + * > + * The framebuffer notifier block > + */ > struct notifier_block fb_notif; > > - /* list entry of all registered backlight devices */ > + /** > + * @entry: > + * > + * List entry of all registered backlight devices > + */ > struct list_head entry; > > + /** > + * @dev: > + * > + * Parent device. > + */ > struct device dev; > > - /* Multiple framebuffers may share one backlight device */ > + /** > + * @fb_bl_on: > + * > + * Multiple fbdev's may share one backlight device. The fb_bl_on > + * records the state of the individual fbdev. > + */ > bool fb_bl_on[FB_MAX]; > > + /** > + * @use_count: > + * > + * The number of uses of fb_bl_on. > + */ > int use_count; > }; > > -- > 2.25.1 >
On Mon, 18 May 2020, Daniel Thompson <daniel.thompson@linaro.org> wrote: > On Sun, May 17, 2020 at 09:01:29PM +0200, Sam Ravnborg wrote: >> Improve the documentation for backlight_device and >> adapt it to kernel-doc style. >> >> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> >> Cc: Lee Jones <lee.jones@linaro.org> >> Cc: Daniel Thompson <daniel.thompson@linaro.org> >> Cc: Jingoo Han <jingoohan1@gmail.com> >> --- >> include/linux/backlight.h | 81 ++++++++++++++++++++++++++++----------- >> 1 file changed, 58 insertions(+), 23 deletions(-) >> >> diff --git a/include/linux/backlight.h b/include/linux/backlight.h >> index 7f9cef299d6e..e2d72936bf05 100644 >> --- a/include/linux/backlight.h >> +++ b/include/linux/backlight.h >> @@ -14,21 +14,6 @@ >> #include <linux/mutex.h> >> #include <linux/notifier.h> >> >> -/* Notes on locking: >> - * >> - * backlight_device->ops_lock is an internal backlight lock protecting the >> - * ops pointer and no code outside the core should need to touch it. >> - * >> - * Access to update_status() is serialised by the update_lock mutex since >> - * most drivers seem to need this and historically get it wrong. >> - * >> - * Most drivers don't need locking on their get_brightness() method. >> - * If yours does, you need to implement it in the driver. You can use the >> - * update_lock mutex if appropriate. >> - * >> - * Any other use of the locks below is probably wrong. >> - */ >> - >> enum backlight_update_reason { >> BACKLIGHT_UPDATE_HOTKEY, >> BACKLIGHT_UPDATE_SYSFS, >> @@ -221,30 +206,80 @@ struct backlight_properties { >> enum backlight_scale scale; >> }; >> >> +/** >> + * struct backlight_device - backlight device data >> + * >> + * This structure holds all data required by a backlight device. >> + */ >> struct backlight_device { >> - /* Backlight properties */ >> + /** >> + * @props: >> + * > > As last patch. Why no brief descriptions? There are no "brief descriptions" in kernel-doc struct member inline markup. It would be possible to shorten this to: /** * @props: Backlight properties */ BR, Jani. > > >> + * Backlight properties >> + */ >> struct backlight_properties props; >> >> - /* Serialise access to update_status method */ >> + /** >> + * @update_lock: >> + * >> + * update_lock is an internal backlight lock that serialise access >> + * to the update_status() method. The iupdate_lock mutex shall not be used >> + * by backlight drivers. > > In addition to the typo this directly contradicts the advice in the > original "Notes on locking". > > A change this dramatic needs to be fully explaining in the patch > description. > > > Daniel. > > >> + */ >> struct mutex update_lock; >> >> - /* This protects the 'ops' field. If 'ops' is NULL, the driver that >> - registered this device has been unloaded, and if class_get_devdata() >> - points to something in the body of that driver, it is also invalid. */ >> + /** >> + * @ops_lock: >> + * >> + * ops_lock is an internal backlight lock that protects the ops pointer >> + * and is used around all accesses to ops and when the operations are >> + * invoked. The mutex shall not be used by backlight drivers. >> + */ >> struct mutex ops_lock; >> + >> + /** >> + * @ops: >> + * >> + * Pointer to the backlight operations. If ops is NULL, the driver that >> + * registered this device has been unloaded, and if class_get_devdata() >> + * points to something in the body of that driver, it is also invalid. >> + */ >> const struct backlight_ops *ops; >> >> - /* The framebuffer notifier block */ >> + /** >> + * @fb_notif: >> + * >> + * The framebuffer notifier block >> + */ >> struct notifier_block fb_notif; >> >> - /* list entry of all registered backlight devices */ >> + /** >> + * @entry: >> + * >> + * List entry of all registered backlight devices >> + */ >> struct list_head entry; >> >> + /** >> + * @dev: >> + * >> + * Parent device. >> + */ >> struct device dev; >> >> - /* Multiple framebuffers may share one backlight device */ >> + /** >> + * @fb_bl_on: >> + * >> + * Multiple fbdev's may share one backlight device. The fb_bl_on >> + * records the state of the individual fbdev. >> + */ >> bool fb_bl_on[FB_MAX]; >> >> + /** >> + * @use_count: >> + * >> + * The number of uses of fb_bl_on. >> + */ >> int use_count; >> }; >> >> -- >> 2.25.1 >>
On Mon, May 18, 2020 at 08:03:21PM +0300, Jani Nikula wrote: > On Mon, 18 May 2020, Daniel Thompson <daniel.thompson@linaro.org> wrote: > > On Sun, May 17, 2020 at 09:01:29PM +0200, Sam Ravnborg wrote: > >> Improve the documentation for backlight_device and > >> adapt it to kernel-doc style. > >> > >> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> > >> Cc: Lee Jones <lee.jones@linaro.org> > >> Cc: Daniel Thompson <daniel.thompson@linaro.org> > >> Cc: Jingoo Han <jingoohan1@gmail.com> > >> --- > >> include/linux/backlight.h | 81 ++++++++++++++++++++++++++++----------- > >> 1 file changed, 58 insertions(+), 23 deletions(-) > >> > >> diff --git a/include/linux/backlight.h b/include/linux/backlight.h > >> index 7f9cef299d6e..e2d72936bf05 100644 > >> --- a/include/linux/backlight.h > >> +++ b/include/linux/backlight.h > >> @@ -14,21 +14,6 @@ > >> #include <linux/mutex.h> > >> #include <linux/notifier.h> > >> > >> -/* Notes on locking: > >> - * > >> - * backlight_device->ops_lock is an internal backlight lock protecting the > >> - * ops pointer and no code outside the core should need to touch it. > >> - * > >> - * Access to update_status() is serialised by the update_lock mutex since > >> - * most drivers seem to need this and historically get it wrong. > >> - * > >> - * Most drivers don't need locking on their get_brightness() method. > >> - * If yours does, you need to implement it in the driver. You can use the > >> - * update_lock mutex if appropriate. > >> - * > >> - * Any other use of the locks below is probably wrong. > >> - */ > >> - > >> enum backlight_update_reason { > >> BACKLIGHT_UPDATE_HOTKEY, > >> BACKLIGHT_UPDATE_SYSFS, > >> @@ -221,30 +206,80 @@ struct backlight_properties { > >> enum backlight_scale scale; > >> }; > >> > >> +/** > >> + * struct backlight_device - backlight device data > >> + * > >> + * This structure holds all data required by a backlight device. > >> + */ > >> struct backlight_device { > >> - /* Backlight properties */ > >> + /** > >> + * @props: > >> + * > > > > As last patch. Why no brief descriptions? > > There are no "brief descriptions" in kernel-doc struct member inline > markup. > > It would be possible to shorten this to: > > /** > * @props: Backlight properties > */ Sorry. Loose phrasing on my part... basically the question is why deviate from the form proposed in "Writing kernel-doc comments"? Daniel. > > > >> + * Backlight properties > >> + */ > >> struct backlight_properties props; > >> > >> - /* Serialise access to update_status method */ > >> + /** > >> + * @update_lock: > >> + * > >> + * update_lock is an internal backlight lock that serialise access > >> + * to the update_status() method. The iupdate_lock mutex shall not be used > >> + * by backlight drivers. > > > > In addition to the typo this directly contradicts the advice in the > > original "Notes on locking". > > > > A change this dramatic needs to be fully explaining in the patch > > description. > > > > > > Daniel. > > > > > >> + */ > >> struct mutex update_lock; > >> > >> - /* This protects the 'ops' field. If 'ops' is NULL, the driver that > >> - registered this device has been unloaded, and if class_get_devdata() > >> - points to something in the body of that driver, it is also invalid. */ > >> + /** > >> + * @ops_lock: > >> + * > >> + * ops_lock is an internal backlight lock that protects the ops pointer > >> + * and is used around all accesses to ops and when the operations are > >> + * invoked. The mutex shall not be used by backlight drivers. > >> + */ > >> struct mutex ops_lock; > >> + > >> + /** > >> + * @ops: > >> + * > >> + * Pointer to the backlight operations. If ops is NULL, the driver that > >> + * registered this device has been unloaded, and if class_get_devdata() > >> + * points to something in the body of that driver, it is also invalid. > >> + */ > >> const struct backlight_ops *ops; > >> > >> - /* The framebuffer notifier block */ > >> + /** > >> + * @fb_notif: > >> + * > >> + * The framebuffer notifier block > >> + */ > >> struct notifier_block fb_notif; > >> > >> - /* list entry of all registered backlight devices */ > >> + /** > >> + * @entry: > >> + * > >> + * List entry of all registered backlight devices > >> + */ > >> struct list_head entry; > >> > >> + /** > >> + * @dev: > >> + * > >> + * Parent device. > >> + */ > >> struct device dev; > >> > >> - /* Multiple framebuffers may share one backlight device */ > >> + /** > >> + * @fb_bl_on: > >> + * > >> + * Multiple fbdev's may share one backlight device. The fb_bl_on > >> + * records the state of the individual fbdev. > >> + */ > >> bool fb_bl_on[FB_MAX]; > >> > >> + /** > >> + * @use_count: > >> + * > >> + * The number of uses of fb_bl_on. > >> + */ > >> int use_count; > >> }; > >> > >> -- > >> 2.25.1 > >> > > -- > Jani Nikula, Intel Open Source Graphics Center
diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 7f9cef299d6e..e2d72936bf05 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -14,21 +14,6 @@ #include <linux/mutex.h> #include <linux/notifier.h> -/* Notes on locking: - * - * backlight_device->ops_lock is an internal backlight lock protecting the - * ops pointer and no code outside the core should need to touch it. - * - * Access to update_status() is serialised by the update_lock mutex since - * most drivers seem to need this and historically get it wrong. - * - * Most drivers don't need locking on their get_brightness() method. - * If yours does, you need to implement it in the driver. You can use the - * update_lock mutex if appropriate. - * - * Any other use of the locks below is probably wrong. - */ - enum backlight_update_reason { BACKLIGHT_UPDATE_HOTKEY, BACKLIGHT_UPDATE_SYSFS, @@ -221,30 +206,80 @@ struct backlight_properties { enum backlight_scale scale; }; +/** + * struct backlight_device - backlight device data + * + * This structure holds all data required by a backlight device. + */ struct backlight_device { - /* Backlight properties */ + /** + * @props: + * + * Backlight properties + */ struct backlight_properties props; - /* Serialise access to update_status method */ + /** + * @update_lock: + * + * update_lock is an internal backlight lock that serialise access + * to the update_status() method. The iupdate_lock mutex shall not be used + * by backlight drivers. + */ struct mutex update_lock; - /* This protects the 'ops' field. If 'ops' is NULL, the driver that - registered this device has been unloaded, and if class_get_devdata() - points to something in the body of that driver, it is also invalid. */ + /** + * @ops_lock: + * + * ops_lock is an internal backlight lock that protects the ops pointer + * and is used around all accesses to ops and when the operations are + * invoked. The mutex shall not be used by backlight drivers. + */ struct mutex ops_lock; + + /** + * @ops: + * + * Pointer to the backlight operations. If ops is NULL, the driver that + * registered this device has been unloaded, and if class_get_devdata() + * points to something in the body of that driver, it is also invalid. + */ const struct backlight_ops *ops; - /* The framebuffer notifier block */ + /** + * @fb_notif: + * + * The framebuffer notifier block + */ struct notifier_block fb_notif; - /* list entry of all registered backlight devices */ + /** + * @entry: + * + * List entry of all registered backlight devices + */ struct list_head entry; + /** + * @dev: + * + * Parent device. + */ struct device dev; - /* Multiple framebuffers may share one backlight device */ + /** + * @fb_bl_on: + * + * Multiple fbdev's may share one backlight device. The fb_bl_on + * records the state of the individual fbdev. + */ bool fb_bl_on[FB_MAX]; + /** + * @use_count: + * + * The number of uses of fb_bl_on. + */ int use_count; };
Improve the documentation for backlight_device and adapt it to kernel-doc style. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Lee Jones <lee.jones@linaro.org> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jingoo Han <jingoohan1@gmail.com> --- include/linux/backlight.h | 81 ++++++++++++++++++++++++++++----------- 1 file changed, 58 insertions(+), 23 deletions(-)