[PATCH] mmc: core: proper ocr negotiation during resume

[PATCH] mmc: core: proper ocr negotiation during resume

[Prasanna NAVARATNA]

>From ad70dbd00db355d1e8ca08e7ad12e73cb41df960 Mon Sep 17 00:00:00 2001
From: Prasanna NAVARATNA <prasanna.navaratna@broadcom.com>
Date: Thu, 4 Apr 2013 19:55:19 +0530
Subject: [PATCH] mmc: core: proper ocr negotiation during resume

Save the card ocr into struct mmc_card when read from card
during initialization of sd/mmc/sdio.
Druing mmc_resume_host, supply saved card's ocr to
mmc_select_voltage so as to negotiate voltage appropriately.
---
 drivers/mmc/core/core.c  |    2 +-
 drivers/mmc/core/mmc.c   |    3 +++
 drivers/mmc/core/sd.c    |    3 +++
 drivers/mmc/core/sdio.c  |    3 +++
 include/linux/mmc/card.h |    1 +
 5 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index ad7decc..aad511a 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2680,7 +2680,7 @@ 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);
+			mmc_select_voltage(host, host->card->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 d584f7c..923eb53 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1566,6 +1566,9 @@ int mmc_attach_mmc(struct mmc_host *host)
 		ocr &= ~0x7F;
 	}
 
+	/* Save the card OCR */
+	host->card->ocr = ocr;
+
 	host->ocr = mmc_select_voltage(host, ocr);
 
 	/*
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 9e645e1..965504b 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1185,6 +1185,9 @@ 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/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index aa0719a..3f9e08d 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -1090,6 +1090,9 @@ int mmc_attach_sdio(struct mmc_host *host)
 		ocr &= ~0x7F;
 	}
 
+	/* 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

Note :- 
1. mmc_select_voltage(host, host->card->ocr);
Here host->card->ocr is directly dereferenced because during resume, we will 
always have host->card !

2. Similar to rca, cid, csa, better to have "ocr" structure member in 
"struct mmc_card" which is card specific and hopefully ocr field might be 
helpful in future too.

Regards,
Prasanna NAVARATNA