On Tue, Oct 19, 2010 at 8:09 AM, Ben Dooks <[email protected]> wrote: > On 12/10/10 01:39, Jaecheol Lee wrote: >> From: Minho Ban <[email protected]> >> >> The clk_enable() and clk_disable() can be used process and ISR either. >> So spin_lock_irqsave should be used instead. >> >> Signed-off-by: Minho Ban <[email protected]> >> Signed-off-by: Jaecheol Lee <[email protected]> >> --- >> arch/arm/plat-samsung/clock.c | 12 ++++++++---- >> 1 files changed, 8 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/plat-samsung/clock.c b/arch/arm/plat-samsung/clock.c >> index e8d20b0..2a991a5 100644 >> --- a/arch/arm/plat-samsung/clock.c >> +++ b/arch/arm/plat-samsung/clock.c >> @@ -138,31 +138,35 @@ void clk_put(struct clk *clk) >> >> int clk_enable(struct clk *clk) >> { >> + unsigned long flags; >> + >> if (IS_ERR(clk) || clk == NULL) >> return -EINVAL; >> >> clk_enable(clk->parent); >> >> - spin_lock(&clocks_lock); >> + spin_lock_irqsave(&clocks_lock, flags); >> >> if ((clk->usage++) == 0) >> (clk->enable)(clk, 1); >> >> - spin_unlock(&clocks_lock); >> + spin_unlock_irqrestore(&clocks_lock, flags); >> return 0; >> } >> >> void clk_disable(struct clk *clk) >> { >> + unsigned long flags; >> + >> if (IS_ERR(clk) || clk == NULL) >> return; >> >> - spin_lock(&clocks_lock); >> + spin_lock_irqsave(&clocks_lock, flags); >> >> if ((--clk->usage) == 0) >> (clk->enable)(clk, 0); >> >> - spin_unlock(&clocks_lock); >> + spin_unlock_irqrestore(&clocks_lock, flags); >> clk_disable(clk->parent); > > I'm not sure, but I don't belive that the clk_ api has > ever been callable from non-sleepable contexts such as > interrupt handlers. > > I would welcome RMK's response (or any other response) > about this issue? > > Personally, given that some clk_ calls may sleep esp. > for pll enables, I would prefer to see this patch > dropped in favour of fixing the users.
I tend to agree. I would like to know any such case where enabling/disabling of some clock is so urgent as to require doing from ISR and not from a tasklet scheduled from ISR. Also let us not make it impossible in future to switch to common clock api by Jeremy Kerr, that doesn't allow calls from IRQ context. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
