> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Prasanna NAVARATNA
> Sent: Thursday, April 04, 2013 10:35 PM
> To: [email protected]
> Subject: mmc: core: negotiate ocr during resume
>
> From f43005e05f1e9d93705ec6b3ab98cfa5215c1896 Mon Sep 17 00:00:00 2001
> From: Prasanna NAVARATNA <[email protected]>
> Date: Thu, 4 Apr 2013 19:55:19 +0530
> Subject: [PATCH] mmc: core: negotiate ocr during resume
>
> Save the card ocr into struct mmc_card when read from sd card and
> negotiate ocr mask during mmc_sd_init_card with host->ocr & card->ocr.
> ---
> drivers/mmc/core/sd.c | 7 +++++++
> include/linux/mmc/card.h | 1 +
> 2 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index 9e645e1..8ee27e8 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -910,6 +910,10 @@ static int mmc_sd_init_card(struct mmc_host *host, u32
> ocr,
> BUG_ON(!host);
> WARN_ON(!host->claimed);
>
> + /* Negotiate OCR with oldcard->ocr */
> + if (oldcard)
> + ocr &= oldcard->ocr;
> +
I think there are several issues here:
1. with this patch the vmmc voltage should still be 3.3v after resume
back since the vmmc voltage is updated in set_ios which depend on
mmc_select_voltage. But mmc_select_voltage didn't notice your ocr
update.
2. you didn't handle the special case that the card is changed to a
new card during suspended. So the ocr may be different here.
3. mmc.c and sdio.c should also be updated besides sd.c.
I have another old version of this patch attached below for your reference:
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index aaed768..f3c7b33 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1351,6 +1351,7 @@ void mmc_power_off(struct mmc_host *host)
* Reset ocr mask to be the highest possible voltage supported for
* this mmc host. This value will be used at next power up.
*/
+ host->ocr_bak = host->ocr;
host->ocr = 1 << (fls(host->ocr_avail) - 1);
if (!mmc_host_is_spi(host)) {
@@ -2491,7 +2492,6 @@ int mmc_resume_host(struct mmc_host *host)
if (host->bus_ops && !host->bus_dead) {
if (!mmc_card_keep_power(host)) {
mmc_power_up(host);
- mmc_select_voltage(host, host->ocr);
/*
* Tell runtime PM core we just powered up the card,
* since it still believes the card is powered off.
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index e6e3911..a8e81d2 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -882,7 +882,9 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
err = -ENOENT;
goto err;
}
-
+ /* restore ocr for the same card */
+ if (host->ocr_bak && (host->ocr_bak != host->ocr))
+ host->ocr = mmc_select_voltage(host, host->ocr_bak);
card = oldcard;
} else {
/*
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 3dafb54..2eea1ae 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -908,7 +908,9 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
if (oldcard) {
if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0)
return -ENOENT;
-
+ /* restore ocr for the same card */
+ if (host->ocr_bak && (host->ocr_bak != host->ocr))
+ host->ocr = mmc_select_voltage(host, host->ocr_bak);
card = oldcard;
} else {
/*
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 2273ce6..f66cc9a 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -594,6 +594,11 @@ static int mmc_sdio_init_card(struct mmc_host
*host, u32 ocr,
err = mmc_send_io_op_cond(host, host->ocr, &ocr);
if (err)
goto err;
+ if (oldcard) {
+ /* restore ocr for the same card */
+ if (host->ocr_bak && (host->ocr_bak != host->ocr))
+ host->ocr = mmc_select_voltage(host,
host->ocr_bak);
+ }
}
/*
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index a90ea7b..ae5533e 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -285,6 +285,7 @@ struct mmc_host {
struct mmc_ios ios; /* current io bus settings */
u32 ocr; /* the current OCR setting */
+ u32 ocr_bak; /* save current OCR setting */
/* group bitfields together to minimize padding */
unsigned int use_spi_crc:1;
Thanks
Kevin
> err = mmc_sd_get_cid(host, ocr, cid, &rocr);
> if (err)
> return err;
> @@ -1185,6 +1189,9 @@ int mmc_attach_sd(struct mmc_host *host)
> ocr &= ~MMC_VDD_165_195;
> }
>
> + /* Save the card OCR */
> + host->card->ocr = ocr;
> +
> host->ocr = mmc_select_voltage(host, ocr);
>
> /*
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index f31725b..1bbec2f 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -273,6 +273,7 @@ struct mmc_card {
> u32 raw_cid[4]; /* raw card CID */
> u32 raw_csd[4]; /* raw card CSD */
> u32 raw_scr[2]; /* raw card SCR */
> + u32 ocr; /* card OCR */
> struct mmc_cid cid; /* card identification */
> struct mmc_csd csd; /* card specific */
> struct mmc_ext_csd ext_csd; /* mmc v4 extended card
> specific */
> --
> 1.7.6
>
>
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