From 5d45b011c14a791ef23555a59ff7a3e6d213530f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 7 Dec 2016 16:22:15 +0100 Subject: [PATCH 1/4] ARM: davinci: da850: fix infinite loop in clk_set_rate() The aemif clock is added twice to the lookup table in da850.c. This breaks the children list of pll0_sysclk3 as we're using the same list links in struct clk. When calling clk_set_rate(), we get stuck in propagate_rate(). Create a separate clock for nand, inheriting the rate of the aemif clock and retrieve it in the davinci_nand module. Cc: # 4.9.x Signed-off-by: Bartosz Golaszewski Signed-off-by: Sekhar Nori --- arch/arm/mach-davinci/da850.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c index e770c97ea45c..e9d019cc8f46 100644 --- a/arch/arm/mach-davinci/da850.c +++ b/arch/arm/mach-davinci/da850.c @@ -367,6 +367,16 @@ static struct clk aemif_clk = { .flags = ALWAYS_ENABLED, }; +/* + * In order to avoid adding the aemif_clk to the clock lookup table twice (and + * screwing up the linked list in the process) create a separate clock for + * nand inheriting the rate from aemif_clk. + */ +static struct clk aemif_nand_clk = { + .name = "nand", + .parent = &aemif_clk, +}; + static struct clk usb11_clk = { .name = "usb11", .parent = &pll0_sysclk4, @@ -537,7 +547,15 @@ static struct clk_lookup da850_clks[] = { CLK("da830-mmc.0", NULL, &mmcsd0_clk), CLK("da830-mmc.1", NULL, &mmcsd1_clk), CLK("ti-aemif", NULL, &aemif_clk), - CLK(NULL, "aemif", &aemif_clk), + /* + * The only user of this clock is davinci_nand and it get's it through + * con_id. The nand node itself is created from within the aemif + * driver to guarantee that it's probed after the aemif timing + * parameters are configured. of_dev_auxdata is not accessible from + * the aemif driver and can't be passed to of_platform_populate(). For + * that reason we're leaving the dev_id here as NULL. + */ + CLK(NULL, "aemif", &aemif_nand_clk), CLK("ohci-da8xx", "usb11", &usb11_clk), CLK("musb-da8xx", "usb20", &usb20_clk), CLK("spi_davinci.0", NULL, &spi0_clk), From ef37427ac5677331145ab27a17e6f5f1b43f0c11 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 7 Dec 2016 16:22:16 +0100 Subject: [PATCH 2/4] ARM: davinci: da850: don't add emac clock to lookup table twice Similarly to the aemif clock - this screws up the linked list of clock children. Create a separate clock for mdio inheriting the rate from emac_clk. Cc: # 3.12.x- Signed-off-by: Bartosz Golaszewski [nsekhar@ti.com: add a comment over mdio_clk to explaing its existence + commit headline updates] Signed-off-by: Sekhar Nori --- arch/arm/mach-davinci/da850.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c index e9d019cc8f46..1d873d15b545 100644 --- a/arch/arm/mach-davinci/da850.c +++ b/arch/arm/mach-davinci/da850.c @@ -319,6 +319,16 @@ static struct clk emac_clk = { .gpsc = 1, }; +/* + * In order to avoid adding the emac_clk to the clock lookup table twice (and + * screwing up the linked list in the process) create a separate clock for + * mdio inheriting the rate from emac_clk. + */ +static struct clk mdio_clk = { + .name = "mdio", + .parent = &emac_clk, +}; + static struct clk mcasp_clk = { .name = "mcasp", .parent = &async3_clk, @@ -539,7 +549,7 @@ static struct clk_lookup da850_clks[] = { CLK(NULL, "arm", &arm_clk), CLK(NULL, "rmii", &rmii_clk), CLK("davinci_emac.1", NULL, &emac_clk), - CLK("davinci_mdio.0", "fck", &emac_clk), + CLK("davinci_mdio.0", "fck", &mdio_clk), CLK("davinci-mcasp.0", NULL, &mcasp_clk), CLK("davinci-mcbsp.0", NULL, &mcbsp0_clk), CLK("davinci-mcbsp.1", NULL, &mcbsp1_clk), From 48cd30b49527f04078ef7de217cc188157f76ba6 Mon Sep 17 00:00:00 2001 From: Alexandre Bailon Date: Fri, 9 Dec 2016 17:59:32 +0100 Subject: [PATCH 3/4] ARM: davinci: Make __clk_{enable,disable} functions public In some cases, there is a need to enable a clock as part of clock enable callback of a different clock. For example, USB 2.0 PHY clock enable requires USB 2.0 clock to be enabled. In this case, it is safe to instead call __clk_enable() since the clock framework lock is already taken. Calling clk_enable() causes recursive locking error. A similar case arises in the clock disable path. To enable such usage, make __clk_{enable,disable} functions publicly available outside of clock.c. Also, call them davinci_clk_{enable|disable} now to be consistent with how other davinci-specific clock functions are named. Note that these functions are not exported to drivers. They are meant for usage in platform specific clock management code. Signed-off-by: Alexandre Bailon Suggested-by: David Lechner Signed-off-by: Sekhar Nori --- arch/arm/mach-davinci/clock.c | 12 ++++++------ arch/arm/mach-davinci/clock.h | 2 ++ 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c index df42c93a93d6..f5dce9b4e617 100644 --- a/arch/arm/mach-davinci/clock.c +++ b/arch/arm/mach-davinci/clock.c @@ -31,10 +31,10 @@ static LIST_HEAD(clocks); static DEFINE_MUTEX(clocks_mutex); static DEFINE_SPINLOCK(clockfw_lock); -static void __clk_enable(struct clk *clk) +void davinci_clk_enable(struct clk *clk) { if (clk->parent) - __clk_enable(clk->parent); + davinci_clk_enable(clk->parent); if (clk->usecount++ == 0) { if (clk->flags & CLK_PSC) davinci_psc_config(clk->domain, clk->gpsc, clk->lpsc, @@ -44,7 +44,7 @@ static void __clk_enable(struct clk *clk) } } -static void __clk_disable(struct clk *clk) +void davinci_clk_disable(struct clk *clk) { if (WARN_ON(clk->usecount == 0)) return; @@ -56,7 +56,7 @@ static void __clk_disable(struct clk *clk) clk->clk_disable(clk); } if (clk->parent) - __clk_disable(clk->parent); + davinci_clk_disable(clk->parent); } int davinci_clk_reset(struct clk *clk, bool reset) @@ -103,7 +103,7 @@ int clk_enable(struct clk *clk) return -EINVAL; spin_lock_irqsave(&clockfw_lock, flags); - __clk_enable(clk); + davinci_clk_enable(clk); spin_unlock_irqrestore(&clockfw_lock, flags); return 0; @@ -118,7 +118,7 @@ void clk_disable(struct clk *clk) return; spin_lock_irqsave(&clockfw_lock, flags); - __clk_disable(clk); + davinci_clk_disable(clk); spin_unlock_irqrestore(&clockfw_lock, flags); } EXPORT_SYMBOL(clk_disable); diff --git a/arch/arm/mach-davinci/clock.h b/arch/arm/mach-davinci/clock.h index e2a5437a1aee..fa2b83752e03 100644 --- a/arch/arm/mach-davinci/clock.h +++ b/arch/arm/mach-davinci/clock.h @@ -132,6 +132,8 @@ int davinci_set_sysclk_rate(struct clk *clk, unsigned long rate); int davinci_set_refclk_rate(unsigned long rate); int davinci_simple_set_rate(struct clk *clk, unsigned long rate); int davinci_clk_reset(struct clk *clk, bool reset); +void davinci_clk_enable(struct clk *clk); +void davinci_clk_disable(struct clk *clk); extern struct platform_device davinci_wdt_device; extern void davinci_watchdog_reset(struct platform_device *); From d1df1e01af1d7c91e48204b9eb8b9f20cdb90700 Mon Sep 17 00:00:00 2001 From: Alexandre Bailon Date: Fri, 9 Dec 2016 17:59:33 +0100 Subject: [PATCH 4/4] ARM: davinci: da8xx: Fix sleeping function called from invalid context Everytime the usb20 phy is enabled, there is a "sleeping function called from invalid context" BUG. In addition, there is a recursive locking happening because of the recurse call to clk_enable(). clk_enable() from arch/arm/mach-davinci/clock.c uses spin_lock_irqsave() before to invoke the callback usb20_phy_clk_enable(). usb20_phy_clk_enable() uses clk_get() and clk_enable_prepapre() which may sleep. Replace clk_prepare_enable() by davinci_clk_enable(). Signed-off-by: Alexandre Bailon Suggested-by: David Lechner [nsekhar@ti.com: minor commit description adjustment] Signed-off-by: Sekhar Nori --- arch/arm/mach-davinci/usb-da8xx.c | 34 ++++++++++++++----------------- 1 file changed, 15 insertions(+), 19 deletions(-) diff --git a/arch/arm/mach-davinci/usb-da8xx.c b/arch/arm/mach-davinci/usb-da8xx.c index c6feecf7ae24..9a6af0bd5dc3 100644 --- a/arch/arm/mach-davinci/usb-da8xx.c +++ b/arch/arm/mach-davinci/usb-da8xx.c @@ -22,6 +22,8 @@ #define DA8XX_USB0_BASE 0x01e00000 #define DA8XX_USB1_BASE 0x01e25000 +static struct clk *usb20_clk; + static struct platform_device da8xx_usb_phy = { .name = "da8xx-usb-phy", .id = -1, @@ -158,26 +160,13 @@ int __init da8xx_register_usb_refclkin(int rate) static void usb20_phy_clk_enable(struct clk *clk) { - struct clk *usb20_clk; - int err; u32 val; u32 timeout = 500000; /* 500 msec */ val = readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG)); - usb20_clk = clk_get(&da8xx_usb20_dev.dev, "usb20"); - if (IS_ERR(usb20_clk)) { - pr_err("could not get usb20 clk: %ld\n", PTR_ERR(usb20_clk)); - return; - } - /* The USB 2.O PLL requires that the USB 2.O PSC is enabled as well. */ - err = clk_prepare_enable(usb20_clk); - if (err) { - pr_err("failed to enable usb20 clk: %d\n", err); - clk_put(usb20_clk); - return; - } + davinci_clk_enable(usb20_clk); /* * Turn on the USB 2.0 PHY, but just the PLL, and not OTG. The USB 1.1 @@ -197,8 +186,7 @@ static void usb20_phy_clk_enable(struct clk *clk) pr_err("Timeout waiting for USB 2.0 PHY clock good\n"); done: - clk_disable_unprepare(usb20_clk); - clk_put(usb20_clk); + davinci_clk_disable(usb20_clk); } static void usb20_phy_clk_disable(struct clk *clk) @@ -285,11 +273,19 @@ static struct clk_lookup usb20_phy_clk_lookup = int __init da8xx_register_usb20_phy_clk(bool use_usb_refclkin) { struct clk *parent; - int ret = 0; + int ret; + + usb20_clk = clk_get(&da8xx_usb20_dev.dev, "usb20"); + ret = PTR_ERR_OR_ZERO(usb20_clk); + if (ret) + return ret; parent = clk_get(NULL, use_usb_refclkin ? "usb_refclkin" : "pll0_aux"); - if (IS_ERR(parent)) - return PTR_ERR(parent); + ret = PTR_ERR_OR_ZERO(parent); + if (ret) { + clk_put(usb20_clk); + return ret; + } usb20_phy_clk.parent = parent; ret = clk_register(&usb20_phy_clk);