[PATCH v1] powerpc: low_i2c: change @lock to raw_spinlock_t
DORMANTno replies
From: John Ogness <john.ogness@linutronix.de>
Date: 2021-02-25 22:07:27
Also in:
lkml
Subsystem:
linux for power macintosh, linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
i2c transfers are occurring with local interrupts disabled:
smp_core99_give_timebase()
local_irq_save();
smp_core99_cypress_tb_freeze()
pmac_i2c_xfer()
kw_i2c_xfer()
spin_lock_irqsave(&host->lock, flags)
This is a problem because with PREEMPT_RT a spinlock_t can sleep,
causing the system to hang. Convert the spinlock_t to the
non-sleeping raw_spinlock_t.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
arch/powerpc/platforms/powermac/low_i2c.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
index f77a59b5c2e1..ba89c95ef290 100644
--- a/arch/powerpc/platforms/powermac/low_i2c.c
+++ b/arch/powerpc/platforms/powermac/low_i2c.c@@ -116,7 +116,7 @@ struct pmac_i2c_host_kw int polled; int result; struct completion complete; - spinlock_t lock; + raw_spinlock_t lock; struct timer_list timeout_timer; };
@@ -346,14 +346,14 @@ static irqreturn_t kw_i2c_irq(int irq, void *dev_id) struct pmac_i2c_host_kw *host = dev_id; unsigned long flags; - spin_lock_irqsave(&host->lock, flags); + raw_spin_lock_irqsave(&host->lock, flags); del_timer(&host->timeout_timer); kw_i2c_handle_interrupt(host, kw_read_reg(reg_isr)); if (host->state != state_idle) { host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT; add_timer(&host->timeout_timer); } - spin_unlock_irqrestore(&host->lock, flags); + raw_spin_unlock_irqrestore(&host->lock, flags); return IRQ_HANDLED; }
@@ -362,7 +362,7 @@ static void kw_i2c_timeout(struct timer_list *t) struct pmac_i2c_host_kw *host = from_timer(host, t, timeout_timer); unsigned long flags; - spin_lock_irqsave(&host->lock, flags); + raw_spin_lock_irqsave(&host->lock, flags); /* * If the timer is pending, that means we raced with the
@@ -377,7 +377,7 @@ static void kw_i2c_timeout(struct timer_list *t) add_timer(&host->timeout_timer); } skip: - spin_unlock_irqrestore(&host->lock, flags); + raw_spin_unlock_irqrestore(&host->lock, flags); } static int kw_i2c_open(struct pmac_i2c_bus *bus)
@@ -470,9 +470,9 @@ static int kw_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize, unsigned long flags; u8 isr = kw_i2c_wait_interrupt(host); - spin_lock_irqsave(&host->lock, flags); + raw_spin_lock_irqsave(&host->lock, flags); kw_i2c_handle_interrupt(host, isr); - spin_unlock_irqrestore(&host->lock, flags); + raw_spin_unlock_irqrestore(&host->lock, flags); } }
@@ -508,7 +508,7 @@ static struct pmac_i2c_host_kw *__init kw_i2c_host_init(struct device_node *np) } mutex_init(&host->mutex); init_completion(&host->complete); - spin_lock_init(&host->lock); + raw_spin_lock_init(&host->lock); timer_setup(&host->timeout_timer, kw_i2c_timeout, 0); psteps = of_get_property(np, "AAPL,address-step", NULL);
--
2.20.1