Hi, > -----Original Message----- > From: Chris Ball [mailto:cjb@xxxxxxxxxx] > Sent: Saturday, March 03, 2012 6:12 AM > To: Chanho Park > Cc: linux-mmc@xxxxxxxxxxxxxxx; Kyungmin Park; Guennadi Liakhovetski > Subject: Re: [PATCH] mmc: core: remove waiting time when clkgate_delay is > set > > Hi, > > On Wed, Feb 29 2012, Chanho Park wrote: > > Since recent commit("mmc: core: Use delayed work in clock gating > > framework":597dd9d79cfbbb1), we always wait "unnecessary" default > > clock delay(8 cycles). Actually, we don't need it if clkgate_delay > > (unit:ms) is set because we already wait sufficient time to change the > > clock due to delayed_workqueue. > > This patch removes duplicated waiting time when clkgate_delay is set. > > > > Signed-off-by: Chanho Park <chanho61.park@xxxxxxxxxxx> > > Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > > --- > > drivers/mmc/core/host.c | 7 +++++-- > > 1 files changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index > > c3704e2..d710ce0 100644 > > --- a/drivers/mmc/core/host.c > > +++ b/drivers/mmc/core/host.c > > @@ -109,8 +109,11 @@ static void mmc_host_clk_gate_delayed(struct > mmc_host *host) > > */ > > if (!host->clk_requests) { > > spin_unlock_irqrestore(&host->clk_lock, flags); > > - tick_ns = DIV_ROUND_UP(1000000000, freq); > > - ndelay(host->clk_delay * tick_ns); > > + /* wait only when clk_gate_delay is 0*/ > > + if (!host->clkgate_delay) { > > + tick_ns = DIV_ROUND_UP(1000000000, freq); > > + ndelay(host->clk_delay * tick_ns); > > + } > > } else { > > /* New users appeared while waiting for this work */ > > spin_unlock_irqrestore(&host->clk_lock, flags); > > Have you seen Guennadi's patch? > > http://git.kernel.org/?p=linux/kernel/git/cjb/mmc.git;a=commitdiff;h=63871 > af54a0f0053de6534afe8da101b988b86b6 I'd already seen the patch. There is no problem if a user didn't set a clkgate_delay. However, if he wants to set a "clkgate_delay", a "clk_delay" is no longer needed. Because, clk_delay(basically 8 cycles) always fall within "clkgate_delay". I remove this "duplicated" wait. Best regards, Chanho Park > > - 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
