On Tue, Feb 22, 2022 at 12:31:10PM +0000, Ricky WU wrote: > > -----Original Message----- > > From: gregkh@xxxxxxxxxxxxxxxxxxx <gregkh@xxxxxxxxxxxxxxxxxxx> > > Sent: Tuesday, February 22, 2022 4:59 PM > > To: Ricky WU <ricky_wu@xxxxxxxxxxx> > > Cc: ulf.hansson@xxxxxxxxxx; kai.heng.feng@xxxxxxxxxxxxx; > > tommyhebb@xxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; > > linux-kernel@xxxxxxxxxxxxxxx > > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > > > On Tue, Feb 22, 2022 at 08:48:30AM +0000, Ricky WU wrote: > > > > -----Original Message----- > > > > From: gregkh@xxxxxxxxxxxxxxxxxxx <gregkh@xxxxxxxxxxxxxxxxxxx> > > > > Sent: Tuesday, February 22, 2022 3:42 PM > > > > To: Ricky WU <ricky_wu@xxxxxxxxxxx> > > > > Cc: ulf.hansson@xxxxxxxxxx; kai.heng.feng@xxxxxxxxxxxxx; > > > > tommyhebb@xxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; > > > > linux-kernel@xxxxxxxxxxxxxxx > > > > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > > > > > > > On Tue, Feb 22, 2022 at 07:27:52AM +0000, Ricky WU wrote: > > > > > After 1ms stabilizing the voltage time add "Host provides at least > > > > > 74 Clocks before issuing first command" that is spec definition > > > > > > > > You do have 72 columns to use here, no need to wrap this so tightly. > > > > > > > > > > Ok... > > > so I need to have next patch to fix this format? > > > > Please do, because: > > > > > > > > > > > > > > > Signed-off-by: Ricky Wu <ricky_wu@xxxxxxxxxxx> > > > > > --- > > > > > drivers/mmc/host/rtsx_pci_sdmmc.c | 7 +++++++ > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > index 2a3f14afe9f8..e016d720e453 100644 > > > > > --- a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > @@ -940,10 +940,17 @@ static int sd_power_on(struct > > > > > realtek_pci_sdmmc > > > > *host) > > > > > if (err < 0) > > > > > return err; > > > > > > > > > > + mdelay(1); > > > > > > > > What is this delay for? > > > > > > > > > > Spec definition, need to wait 1ms for voltage stable and below > > > mdelay(5) is our device send 74 Clocks time > > > > Clock cycles and mdelay() are not going to always stay the same, right? > > > > I really have no idea what "74 clocks time" means, is this some specific timing > > value for this hardware? What is the units? This needs to be documented > > better in both the changelog and in the code. > > > > thanks, > > > > Please ref: https://www.sdcard.org/downloads/pls/ Version8 I can not download those specifications according to the license that they ask me to abide by. > And see the 6.4.1.2 Power Up Time of Host Figure 6-5: Power Up Diagram of Host > mdelay(1) corresponds to Stable supply voltage > mdelay(5) corresponds to Host provides at least 74 Clocks before issuing first command > our device need 5ms to issue 74 Clocks What is a "clock"? The kernel works with time units, how does "5" equal to 74? thanks, greg k-h
