From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
zhang.chunyan@linaro.org,
"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>
Subject: Re: [PATCH] mmc: sdhci: Use Auto CMD Auto Select only when v4_mode is true
Date: Thu, 15 Oct 2020 10:38:40 +0800 [thread overview]
Message-ID: <20201015103840.3935a420@xhacker.debian> (raw)
In-Reply-To: <20201015101207.3a88004e@xhacker.debian>
On Thu, 15 Oct 2020 10:12:07 +0800 Jisheng Zhang wrote:
>
> On Wed, 14 Oct 2020 22:44:50 +0300 Adrian Hunter wrote:
>
> >
> >
> > + Chunyan
> >
> > On 14/10/20 1:32 pm, Jisheng Zhang wrote:
> > > Auto CMD Auto Select can only be used when v4_mode is enabled.
> >
> > The SDHCI spec. doesn't seem to say that. AFAICS it refers only to v4.1 not
> > v4 mode.
>
> 4.10 defines the "Auto CMD Auto Select" mode, v4 mode bit in SDHCI_HOST_CONTROL2
> selects V3 compatible or V4 compatible mode, I think the v4 here includes
> v4.0, v4.1 and v4.2, so if we want to use the mode we have to ensure v4_mode
So if we want to use the "Auto CMD Auto Select" mode, we have to ensure v4 mode
is enabled.
> is enabled.
>
> thanks
>
> >
> > >
> > > Fixes: 427b6514d095 ("mmc: sdhci: Add Auto CMD Auto Select support")
> > > Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> > > ---
> > > drivers/mmc/host/sdhci.c | 3 ++-
> > > 1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > > index 592a55a34b58..5e0ec5df4074 100644
> > > --- a/drivers/mmc/host/sdhci.c
> > > +++ b/drivers/mmc/host/sdhci.c
> > > @@ -1386,7 +1386,8 @@ static inline void sdhci_auto_cmd_select(struct sdhci_host *host,
> > > * Select' is recommended rather than use of 'Auto CMD12
> > > * Enable' or 'Auto CMD23 Enable'.
> > > */
> > > - if (host->version >= SDHCI_SPEC_410 && (use_cmd12 || use_cmd23)) {
> > > + if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
> > > + (use_cmd12 || use_cmd23)) {
> > > *mode |= SDHCI_TRNS_AUTO_SEL;
> > >
> > > ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > >
> >
>
next prev parent reply other threads:[~2020-10-15 2:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-13 11:08 eMMC performance regression caused by 427b6514d0953bf Jisheng Zhang
2020-10-13 12:32 ` Ulf Hansson
2020-10-13 13:23 ` Adrian Hunter
2020-10-14 10:32 ` [PATCH] mmc: sdhci: Use Auto CMD Auto Select only when v4_mode is true Jisheng Zhang
2020-10-14 19:44 ` Adrian Hunter
2020-10-15 2:12 ` Jisheng Zhang
2020-10-15 2:38 ` Jisheng Zhang [this message]
2020-10-15 5:57 ` Adrian Hunter
2020-10-15 6:24 ` Jisheng Zhang
2020-10-15 8:50 ` Adrian Hunter
2020-10-14 10:42 ` eMMC performance regression caused by 427b6514d0953bf Jisheng Zhang
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