| Message ID | 1345058187-18843-1-git-send-email-msb@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Mandeep Singh Baines wrote: > > From 0cdf3aff, "ARM: SAMSUNG: use spin_lock_irqsave() in > clk_{enable,disable}": > > The clk_enable()and clk_disable() can be used process and ISR either. > And actually it is used for real product and other platforms use it > now. So spin_lock_irqsave() should be used instead. > > We need to make a similar change in clk_set_parent(). Otherwise, > you can potentially get spinlock recursion: > > BUG: spinlock recursion on CPU#0, kinteractive/68 > lock: 807832a8, .magic: dead4ead, .owner: kinteractive/68, .owner_cpu: 0 > [<80015f54>] (unwind_backtrace+0x0/0x128) from [<804f2914>] > (dump_stack+0x20/0x24) > [<804f2914>] (dump_stack+0x20/0x24) from [<804f57b8>] (spin_dump+0x80/0x94) > [<804f57b8>] (spin_dump+0x80/0x94) from [<804f57f8>] (spin_bug+0x2c/0x30) > [<804f57f8>] (spin_bug+0x2c/0x30) from [<80222730>] > (do_raw_spin_lock+0x54/0x150) > [<80222730>] (do_raw_spin_lock+0x54/0x150) from [<804f96ec>] > (_raw_spin_lock_irqsave+0x20/0x28) > [<804f96ec>] (_raw_spin_lock_irqsave+0x20/0x28) from [<80022ea4>] > (clk_enable+0x3c/0x84) > [<80022ea4>] (clk_enable+0x3c/0x84) from [<8038336c>] > (s5p_mfc_clock_on+0x60/0x74) > [<8038336c>] (s5p_mfc_clock_on+0x60/0x74) from [<8038645c>] > (s5p_mfc_read_info+0x20/0x38) > [<8038645c>] (s5p_mfc_read_info+0x20/0x38) from [<8037ca3c>] > (s5p_mfc_handle_frame+0x2e4/0x4bc) > [<8037ca3c>] (s5p_mfc_handle_frame+0x2e4/0x4bc) from [<8037d420>] > (s5p_mfc_irq+0x1ec/0x6cc) > [<8037d420>] (s5p_mfc_irq+0x1ec/0x6cc) from [<8007fc74>] > (handle_irq_event_percpu+0x8c/0x244) > [<8007fc74>] (handle_irq_event_percpu+0x8c/0x244) from [<8007fe78>] > (handle_irq_event+0x4c/0x6c) > [<8007fe78>] (handle_irq_event+0x4c/0x6c) from [<80082dd8>] > (handle_fasteoi_irq+0xe4/0x150) > [<80082dd8>] (handle_fasteoi_irq+0xe4/0x150) from [<8007f424>] > (generic_handle_irq+0x3c/0x50) > [<8007f424>] (generic_handle_irq+0x3c/0x50) from [<8000f7c4>] > (handle_IRQ+0x88/0xc8) > [<8000f7c4>] (handle_IRQ+0x88/0xc8) from [<80008564>] > (gic_handle_irq+0x44/0x68) > [<80008564>] (gic_handle_irq+0x44/0x68) from [<8000e400>] > (__irq_svc+0x40/0x60) > Exception stack(0xef3cbe68 to 0xef3cbeb0) > [<8000e400>] (__irq_svc+0x40/0x60) from [<80022cfc>] > (clk_set_parent+0x30/0x74) > [<80022cfc>] (clk_set_parent+0x30/0x74) from [<803ac7f8>] > (set_apll.isra.0+0x28/0xb0) > [<803ac7f8>] (set_apll.isra.0+0x28/0xb0) from [<803ac8e4>] > (exynos5250_set_frequency+0x64/0xb8) > [<803ac8e4>] (exynos5250_set_frequency+0x64/0xb8) from [<803ac280>] > (exynos_target+0x1b0/0x220) > [<803ac280>] (exynos_target+0x1b0/0x220) from [<803a4a0c>] > (__cpufreq_driver_target+0xb0/0xd4) > [<803a4a0c>] (__cpufreq_driver_target+0xb0/0xd4) from [<803aab80>] > (cpufreq_interactive_updown_task+0x214/0x264) > [<803aab80>] (cpufreq_interactive_updown_task+0x214/0x264) from > [<80047d04>] (kthread+0x9c/0xa8) > [<80047d04>] (kthread+0x9c/0xa8) from [<8000fa48>] > (kernel_thread_exit+0x0/0x8) > > Signed-off-by: Mandeep Singh Baines <msb@chromium.org> > Suggested-by: Sunil Mazhavanchery <sunilm@samsung.com> > CC: linux-arm-kernel@lists.infradead.org > CC: linux-samsung-soc@vger.kernel.org > CC: Ben Dooks <ben-linux@fluff.org> > CC: Kukjin Kim <kgene.kim@samsung.com> > CC: Russell King <linux@arm.linux.org.uk> > CC: Minho Ban <mhban@samsung.com> > CC: Jaecheol Lee <jc.lee@samsung.com> > CC: Sunyoung Kang <sy0816.kang@samsung.com> > CC: Kukjin Kim <kgene.kim@samsung.com> > CC: Olof Johansson <olofj@chromium.org> > --- > arch/arm/plat-samsung/clock.c | 5 +++-- > 1 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/plat-samsung/clock.c b/arch/arm/plat-samsung/clock.c > index 65c5eca..80eacca 100644 > --- a/arch/arm/plat-samsung/clock.c > +++ b/arch/arm/plat-samsung/clock.c > @@ -173,17 +173,18 @@ struct clk *clk_get_parent(struct clk *clk) > > int clk_set_parent(struct clk *clk, struct clk *parent) > { > + unsigned long flags; > int ret = 0; > > if (IS_ERR(clk)) > return -EINVAL; > > - spin_lock(&clocks_lock); > + spin_lock_irqsave(&clocks_lock, flags); > > if (clk->ops && clk->ops->set_parent) > ret = (clk->ops->set_parent)(clk, parent); > > - spin_unlock(&clocks_lock); > + spin_unlock_irqrestore(&clocks_lock, flags); > > return ret; > } > -- > 1.7.7.3 Yup, right. Applied. Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim@samsung.com>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd.
diff --git a/arch/arm/plat-samsung/clock.c b/arch/arm/plat-samsung/clock.c index 65c5eca..80eacca 100644 --- a/arch/arm/plat-samsung/clock.c +++ b/arch/arm/plat-samsung/clock.c @@ -173,17 +173,18 @@ struct clk *clk_get_parent(struct clk *clk) int clk_set_parent(struct clk *clk, struct clk *parent) { + unsigned long flags; int ret = 0; if (IS_ERR(clk)) return -EINVAL; - spin_lock(&clocks_lock); + spin_lock_irqsave(&clocks_lock, flags); if (clk->ops && clk->ops->set_parent) ret = (clk->ops->set_parent)(clk, parent); - spin_unlock(&clocks_lock); + spin_unlock_irqrestore(&clocks_lock, flags); return ret; }
From 0cdf3aff, "ARM: SAMSUNG: use spin_lock_irqsave() in clk_{enable,disable}": The clk_enable()and clk_disable() can be used process and ISR either. And actually it is used for real product and other platforms use it now. So spin_lock_irqsave() should be used instead. We need to make a similar change in clk_set_parent(). Otherwise, you can potentially get spinlock recursion: BUG: spinlock recursion on CPU#0, kinteractive/68 lock: 807832a8, .magic: dead4ead, .owner: kinteractive/68, .owner_cpu: 0 [<80015f54>] (unwind_backtrace+0x0/0x128) from [<804f2914>] (dump_stack+0x20/0x24) [<804f2914>] (dump_stack+0x20/0x24) from [<804f57b8>] (spin_dump+0x80/0x94) [<804f57b8>] (spin_dump+0x80/0x94) from [<804f57f8>] (spin_bug+0x2c/0x30) [<804f57f8>] (spin_bug+0x2c/0x30) from [<80222730>] (do_raw_spin_lock+0x54/0x150) [<80222730>] (do_raw_spin_lock+0x54/0x150) from [<804f96ec>] (_raw_spin_lock_irqsave+0x20/0x28) [<804f96ec>] (_raw_spin_lock_irqsave+0x20/0x28) from [<80022ea4>] (clk_enable+0x3c/0x84) [<80022ea4>] (clk_enable+0x3c/0x84) from [<8038336c>] (s5p_mfc_clock_on+0x60/0x74) [<8038336c>] (s5p_mfc_clock_on+0x60/0x74) from [<8038645c>] (s5p_mfc_read_info+0x20/0x38) [<8038645c>] (s5p_mfc_read_info+0x20/0x38) from [<8037ca3c>] (s5p_mfc_handle_frame+0x2e4/0x4bc) [<8037ca3c>] (s5p_mfc_handle_frame+0x2e4/0x4bc) from [<8037d420>] (s5p_mfc_irq+0x1ec/0x6cc) [<8037d420>] (s5p_mfc_irq+0x1ec/0x6cc) from [<8007fc74>] (handle_irq_event_percpu+0x8c/0x244) [<8007fc74>] (handle_irq_event_percpu+0x8c/0x244) from [<8007fe78>] (handle_irq_event+0x4c/0x6c) [<8007fe78>] (handle_irq_event+0x4c/0x6c) from [<80082dd8>] (handle_fasteoi_irq+0xe4/0x150) [<80082dd8>] (handle_fasteoi_irq+0xe4/0x150) from [<8007f424>] (generic_handle_irq+0x3c/0x50) [<8007f424>] (generic_handle_irq+0x3c/0x50) from [<8000f7c4>] (handle_IRQ+0x88/0xc8) [<8000f7c4>] (handle_IRQ+0x88/0xc8) from [<80008564>] (gic_handle_irq+0x44/0x68) [<80008564>] (gic_handle_irq+0x44/0x68) from [<8000e400>] (__irq_svc+0x40/0x60) Exception stack(0xef3cbe68 to 0xef3cbeb0) [<8000e400>] (__irq_svc+0x40/0x60) from [<80022cfc>] (clk_set_parent+0x30/0x74) [<80022cfc>] (clk_set_parent+0x30/0x74) from [<803ac7f8>] (set_apll.isra.0+0x28/0xb0) [<803ac7f8>] (set_apll.isra.0+0x28/0xb0) from [<803ac8e4>] (exynos5250_set_frequency+0x64/0xb8) [<803ac8e4>] (exynos5250_set_frequency+0x64/0xb8) from [<803ac280>] (exynos_target+0x1b0/0x220) [<803ac280>] (exynos_target+0x1b0/0x220) from [<803a4a0c>] (__cpufreq_driver_target+0xb0/0xd4) [<803a4a0c>] (__cpufreq_driver_target+0xb0/0xd4) from [<803aab80>] (cpufreq_interactive_updown_task+0x214/0x264) [<803aab80>] (cpufreq_interactive_updown_task+0x214/0x264) from [<80047d04>] (kthread+0x9c/0xa8) [<80047d04>] (kthread+0x9c/0xa8) from [<8000fa48>] (kernel_thread_exit+0x0/0x8) Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Suggested-by: Sunil Mazhavanchery <sunilm@samsung.com> CC: linux-arm-kernel@lists.infradead.org CC: linux-samsung-soc@vger.kernel.org CC: Ben Dooks <ben-linux@fluff.org> CC: Kukjin Kim <kgene.kim@samsung.com> CC: Russell King <linux@arm.linux.org.uk> CC: Minho Ban <mhban@samsung.com> CC: Jaecheol Lee <jc.lee@samsung.com> CC: Sunyoung Kang <sy0816.kang@samsung.com> CC: Kukjin Kim <kgene.kim@samsung.com> CC: Olof Johansson <olofj@chromium.org> --- arch/arm/plat-samsung/clock.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)