Messages in this thread | | | Subject | Re: [PATCH v4] mmc: dw_mmc: force setup bus if active slots exist | From | Shawn Lin <> | Date | Thu, 5 Jan 2017 15:34:16 +0800 |
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On 2017/1/5 15:23, Ziyuan Xu wrote: > It's necessary to setup bus if any slots are present. > - update clock after ctrl reset > - if the host has genpd node, we can guarantee the clock is available > before starting request. Otherwies, the clock register is reset once > power off the pd, and host can't output the active clock during > communication. > > fixes: e9ed8835e990 ("mmc: dw_mmc: add runtime PM callback") > Reported-by: Randy Li <randy.li@rock-chips.com> > Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com> > > --- > Hi guys, > > I found a similar issue on rk3399 platform, which has a genpd node for > SD card host. Power off-on pd will reset the registers to a default > value (ie. CLKENA), so that the host can't output the active clock > during communication. >
Indeed, Caesar recently introduced all the genpd for rk3399 platform, so we need to restore them.
> So we need to setup bus in rpm resume. It also wraps the update clock > behaviour which I did in V3. > > Thanks, > Ziyuan Xu > > > Changes in v4: > - update commit message > - fix SD host rpm resume can't work > > Changes in v3: > - only reset host with active slot. > > Changes in v2: > - update the commit message > - use dw_mci_reset instead of dw_mci_ctrl_reset > > drivers/mmc/host/dw_mmc.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index b44306b..b6053b3 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -3354,10 +3354,10 @@ int dw_mci_runtime_resume(struct device *dev) > > if (!slot) > continue; > - if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) { > + if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) > dw_mci_set_ios(slot->mmc, &slot->mmc->ios); > - dw_mci_setup_bus(slot, true); > - } > + /* Force setup bus to guarantee available clock output */ > + dw_mci_setup_bus(slot, true);
So the spamming message about
"Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n"
will always be there, right? So you could append a new patch to shut up it as I think it's useless no matter for system pm or rpm to print it. How about?
> } > > /* Now that slots are all setup, we can enable card detect */ >
-- Best Regards Shawn Lin
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