From mboxrd@z Thu Jan 1 00:00:00 1970 From: michal.simek@xilinx.com (Michal Simek) Date: Mon, 14 Aug 2017 16:15:01 +0200 Subject: [PATCH 3/8] gpio: zynq: Shift zynq_gpio_init() to subsys_initcall level In-Reply-To: References: Message-ID: <68cd52a7-ce87-a507-f02d-ccb99634b465@xilinx.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 14.8.2017 15:55, Linus Walleij wrote: > On Mon, Aug 7, 2017 at 1:01 PM, Michal Simek wrote: > >> From: Nava kishore Manne >> >> In general situation on-SoC GPIO controller drivers should be probed >> after pinctrl/pinmux controller driver, because on-SoC GPIOs utilize a >> pin/pad as a resource provided and controlled by pinctrl subsystem. >> >> GPIO must come after pinctrl as gpios may need to mux pins....etc >> >> Looking at Xilinx SoC series pinctrl drivers, zynq*_pinctrl_init() >> functions are called at arch_initcall init levels, >> so the change of initcall level for gpio-zynq driver from >> postcore_initcall to subsys_initcall level is sufficient. Also note >> that the most of GPIO controller drivers settled at subsys_initcall >> level. >> >> If pinctrl subsystem manages pads with GPIO functions, the change is >> needed to avoid unwanted driver probe deferrals during kernel boot. >> >> Signed-off-by: Nava kishore Manne >> Signed-off-by: Michal Simek > > Can't you just move it all the way to device_initcall and > simply use the standard module init macros? > builtin_platform_driver(), module_platform_driver()? When I grep the kernel I see this [linux](master)$ git grep "^core_initcall" drivers/gpio/ | wc -l 1 [linux](master)$ git grep "^postcore_initcall" drivers/gpio/ | wc -l 12 [linux](master)$ git grep "^arch_initcall" drivers/gpio/ | wc -l 2 [linux](master)$ git grep "^subsys_initcall" drivers/gpio/ | wc -l 33 [linux](master)$ git grep "^device_initcall" drivers/gpio/ | wc -l 4 [linux](master)$ git grep "^core_initcall" drivers/pinctrl/ | wc -l 6 [linux](master)$ git grep "^postcore_initcall" drivers/pinctrl/ | wc -l 7 [linux](master)$ git grep "^arch_initcall" drivers/pinctrl/ | wc -l 62 [linux](master)$ git grep "^subsys_initcall" drivers/pinctrl/ | wc -l 12 [linux](master)$ git grep "^device_initcall" drivers/pinctrl/ | wc -l 0 Majority of gpio drivers are in subsys_initcall and pinctrl in arch_initcall. It doesn't mean that I have strong opinion about doing this change. I have also read internal tracking system and it is not fully clear if this is fixing any issue rather than removing on deferring probe message. Nava: Do you have any comment? Thanks, Michal