RE: [PATCH v6 1/3] mmc: core: Add packed command feature of eMMC4.5

From: Subhash Jadavani
Date: Tue May 29 2012 - 08:45:48 EST




> -----Original Message-----
> From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc-
> owner@xxxxxxxxxxxxxxx] On Behalf Of merez@xxxxxxxxxxxxxx
> Sent: Tuesday, May 29, 2012 5:08 PM
> To: Seungwon Jeon
> Cc: linux-mmc@xxxxxxxxxxxxxxx; 'Chris Ball'; merez@xxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v6 1/3] mmc: core: Add packed command feature of
> eMMC4.5
>
> > @@ -1244,6 +1249,25 @@ static int mmc_init_card(struct mmc_host *host,
> > u32 ocr,
> > }
> > }
> >
> > + if ((host->caps2 & MMC_CAP2_PACKED_CMD) &&
> > + (card->ext_csd.max_packed_writes > 0) &&
> > + (card->ext_csd.max_packed_reads > 0)) {
> > + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> > + EXT_CSD_EXP_EVENTS_CTRL,
> > + EXT_CSD_PACKED_EVENT_EN,
> > + card->ext_csd.generic_cmd6_time);
> > + if (err && err != -EBADMSG)
> > + goto free_card;
> > + if (err) {
> > + pr_warning("%s: Enabling packed event failed\n",
> > + mmc_hostname(card->host));
> > + card->ext_csd.packed_event_en = 0;
> > + err = 0;
> > + } else {
> > + card->ext_csd.packed_event_en = 1;
> > + }
> > + }
> > +
> The above shoud not be performed in case of resume. Therefore it needs to
be
> done only if (!oldcard)

Maya,
What if eMMC power (VCC and VCCQ) was removed during suspend? Then in that
case during resume, we have to send this mmc_switch() command again. So this
operation should not be under "if (!oldcard)" check.

Regards,
Subhash


>
> Thanks,
> Maya Erez
> Consultant for Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
>
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