Hi, On Thu, Feb 23 2012, Guennadi Liakhovetski wrote: > A recent commit "mmc: core: Use delayed work in clock gating framework" > introduced a default 200ms delay before clock gating actually takes place. > This means, that every time an MMC interface becomes idle it first stays > on for 200ms before gating its clock. This leads to increased power > consumption and is therefore a clear regression. This patch restores the > original behaviour by setting the default delay to 0. Users, > prioritising throughput over power efficiency can still modify the delay > via sysfs. > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx> > --- > > As discussed in this thread > > http://thread.gmane.org/gmane.linux.kernel.mmc/12307 > > this is one of the ways to fix the regression. Please, push for 3.3. > > drivers/mmc/core/host.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index 30055f2..c3704e2 100644 > --- a/drivers/mmc/core/host.c > +++ b/drivers/mmc/core/host.c > @@ -238,10 +238,10 @@ static inline void mmc_host_clk_init(struct mmc_host *host) > /* Hold MCI clock for 8 cycles by default */ > host->clk_delay = 8; > /* > - * Default clock gating delay is 200ms. > + * Default clock gating delay is 0ms to avoid wasting power. > * This value can be tuned by writing into sysfs entry. > */ > - host->clkgate_delay = 200; > + host->clkgate_delay = 0; > host->clk_gated = false; > INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work); > spin_lock_init(&host->clk_lock); Thanks, will push this to 3.3 this week. - Chris. -- Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/> One Laptop Per Child -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
