This is a note to let you know that I've just added the patch titled
pinctrl: Really force states during suspend/resume
to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: pinctrl-really-force-states-during-suspend-resume.patch and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Mar 22 14:57:33 CET 2018
From: Florian Fainelli f.fainelli@gmail.com Date: Wed, 1 Mar 2017 10:32:57 -0800 Subject: pinctrl: Really force states during suspend/resume
From: Florian Fainelli f.fainelli@gmail.com
[ Upstream commit 981ed1bfbc6c4660b2ddaa8392893e20a6255048 ]
In case a platform only defaults a "default" set of pins, but not a "sleep" set of pins, and this particular platform suspends and resumes in a way that the pin states are not preserved by the hardware, when we resume, we would call pinctrl_single_resume() -> pinctrl_force_default() -> pinctrl_select_state() and the first thing we do is check that the pins state is the same as before, and do nothing.
In order to fix this, decouple the actual state change from pinctrl_select_state() and move it pinctrl_commit_state(), while keeping the p->state == state check in pinctrl_select_state() not to change the caller assumptions. pinctrl_force_sleep() and pinctrl_force_default() are updated to bypass the state check by calling pinctrl_commit_state().
[Linus Walleij] The forced pin control states are currently only used in some pin controller drivers that grab their own reference to their own pins. This is equal to the pin control hogs: pins taken by pin control devices since there are no corresponding device in the Linux device hierarchy, such as memory controller lines or unused GPIO lines, or GPIO lines that are used orthogonally from the GPIO subsystem but pincontrol-wise managed as hogs (non-strict mode, allowing simultaneous use by GPIO and pin control). For this case forcing the state from the drivers' suspend()/resume() callbacks makes sense and should semantically match the name of the function.
Fixes: 6e5e959dde0d ("pinctrl: API changes to support multiple states per device") Signed-off-by: Florian Fainelli f.fainelli@gmail.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pinctrl/core.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-)
--- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -979,19 +979,16 @@ struct pinctrl_state *pinctrl_lookup_sta EXPORT_SYMBOL_GPL(pinctrl_lookup_state);
/** - * pinctrl_select_state() - select/activate/program a pinctrl state to HW + * pinctrl_commit_state() - select/activate/program a pinctrl state to HW * @p: the pinctrl handle for the device that requests configuration * @state: the state handle to select/activate/program */ -int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state) +static int pinctrl_commit_state(struct pinctrl *p, struct pinctrl_state *state) { struct pinctrl_setting *setting, *setting2; struct pinctrl_state *old_state = p->state; int ret;
- if (p->state == state) - return 0; - if (p->state) { /* * For each pinmux setting in the old state, forget SW's record @@ -1055,6 +1052,19 @@ unapply_new_state:
return ret; } + +/** + * pinctrl_select_state() - select/activate/program a pinctrl state to HW + * @p: the pinctrl handle for the device that requests configuration + * @state: the state handle to select/activate/program + */ +int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state) +{ + if (p->state == state) + return 0; + + return pinctrl_commit_state(p, state); +} EXPORT_SYMBOL_GPL(pinctrl_select_state);
static void devm_pinctrl_release(struct device *dev, void *res) @@ -1223,7 +1233,7 @@ void pinctrl_unregister_map(struct pinct int pinctrl_force_sleep(struct pinctrl_dev *pctldev) { if (!IS_ERR(pctldev->p) && !IS_ERR(pctldev->hog_sleep)) - return pinctrl_select_state(pctldev->p, pctldev->hog_sleep); + return pinctrl_commit_state(pctldev->p, pctldev->hog_sleep); return 0; } EXPORT_SYMBOL_GPL(pinctrl_force_sleep); @@ -1235,7 +1245,7 @@ EXPORT_SYMBOL_GPL(pinctrl_force_sleep); int pinctrl_force_default(struct pinctrl_dev *pctldev) { if (!IS_ERR(pctldev->p) && !IS_ERR(pctldev->hog_default)) - return pinctrl_select_state(pctldev->p, pctldev->hog_default); + return pinctrl_commit_state(pctldev->p, pctldev->hog_default); return 0; } EXPORT_SYMBOL_GPL(pinctrl_force_default);
Patches currently in stable-queue which might be from f.fainelli@gmail.com are
queue-4.4/pinctrl-really-force-states-during-suspend-resume.patch