diff mbox

[02/10] mmc: block: add block number limitation flag for multiple block read

Message ID 87bnsihs8l.wl%kuninori.morimoto.gx@renesas.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kuninori Morimoto July 22, 2014, 5:34 a.m. UTC 
From: Shinobu Uehara <shinobu.uehara.xc@renesas.com>

In some controllers, when performing a multiple block read of
one or two blocks, depending on the timing with which the
response register is read, the response value may not
be read properly.
MMC_CAP2_NO_MULTI_READ flags disable all multiple block read,
but, it is over-kill for this issue.
This patch adds new MMC_CAP2_2BLKS_LIMIT to use single block read
when it was two blocks.
This is additional option of MMC_CAP2_NO_MULTI_READ

[Kuninori Morimoto: tidyup for upstreaming, and cared mach-shmobile]

Signed-off-by: Shinobu Uehara <shinobu.uehara.xc@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
---
 arch/arm/mach-shmobile/board-koelsch.c |    6 +++---
 arch/arm/mach-shmobile/board-lager.c   |    4 ++--
 drivers/mmc/card/block.c               |   19 +++++++++++++++++--
 drivers/mmc/host/sh_mobile_sdhi.c      |    2 +-
 include/linux/mmc/host.h               |    3 +++
 5 files changed, 26 insertions(+), 8 deletions(-)
diff mbox

Patch

diff --git a/arch/arm/mach-shmobile/board-koelsch.c b/arch/arm/mach-shmobile/board-koelsch.c
index 2cd3194..4936436 100644
--- a/arch/arm/mach-shmobile/board-koelsch.c
+++ b/arch/arm/mach-shmobile/board-koelsch.c
@@ -333,7 +333,7 @@  SDHI_REGULATOR(2, RCAR_GP_PIN(7, 19), RCAR_GP_PIN(2, 26));
 static struct sh_mobile_sdhi_info sdhi0_info __initdata = {
 	.tmio_caps	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 			  MMC_CAP_POWER_OFF_CARD,
-	.tmio_caps2	= MMC_CAP2_NO_MULTI_READ,
+	.tmio_caps2	= MMC_CAP2_NO_2BLKS_READ,
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT,
 };
 
@@ -346,7 +346,7 @@  static struct resource sdhi0_resources[] __initdata = {
 static struct sh_mobile_sdhi_info sdhi1_info __initdata = {
 	.tmio_caps	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 			  MMC_CAP_POWER_OFF_CARD,
-	.tmio_caps2	= MMC_CAP2_NO_MULTI_READ,
+	.tmio_caps2	= MMC_CAP2_NO_2BLKS_READ,
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT,
 };
 
@@ -359,7 +359,7 @@  static struct resource sdhi1_resources[] __initdata = {
 static struct sh_mobile_sdhi_info sdhi2_info __initdata = {
 	.tmio_caps	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 			  MMC_CAP_POWER_OFF_CARD,
-	.tmio_caps2	= MMC_CAP2_NO_MULTI_READ,
+	.tmio_caps2	= MMC_CAP2_NO_2BLKS_READ,
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT |
 			  TMIO_MMC_WRPROTECT_DISABLE,
 };
diff --git a/arch/arm/mach-shmobile/board-lager.c b/arch/arm/mach-shmobile/board-lager.c
index b8b2b44..ad85f9d 100644
--- a/arch/arm/mach-shmobile/board-lager.c
+++ b/arch/arm/mach-shmobile/board-lager.c
@@ -634,7 +634,7 @@  static void __init lager_add_rsnd_device(void)
 static struct sh_mobile_sdhi_info sdhi0_info __initdata = {
 	.tmio_caps	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 			  MMC_CAP_POWER_OFF_CARD,
-	.tmio_caps2	= MMC_CAP2_NO_MULTI_READ,
+	.tmio_caps2	= MMC_CAP2_NO_2BLKS_READ,
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT |
 			  TMIO_MMC_WRPROTECT_DISABLE,
 };
@@ -648,7 +648,7 @@  static struct resource sdhi0_resources[] __initdata = {
 static struct sh_mobile_sdhi_info sdhi2_info __initdata = {
 	.tmio_caps	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 			  MMC_CAP_POWER_OFF_CARD,
-	.tmio_caps2	= MMC_CAP2_NO_MULTI_READ,
+	.tmio_caps2	= MMC_CAP2_NO_2BLKS_READ,
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT |
 			  TMIO_MMC_WRPROTECT_DISABLE,
 };
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 452782b..f3cbe37 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1400,8 +1400,23 @@  static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
 
 		/* Some controllers can't do multiblock reads due to hw bugs */
 		if (card->host->caps2 & MMC_CAP2_NO_MULTI_READ &&
-		    rq_data_dir(req) == READ)
-			brq->data.blocks = 1;
+		    rq_data_dir(req) == READ) {
+
+			if (card->host->caps2 & MMC_CAP2_2BLKS_LIMIT) {
+				/*
+				 * In some controllers, when performing a
+				 * multiple block read of one or two blocks,
+				 * depending on the timing with which the
+				 * response register is read, the response
+				 * value may not be read properly.
+				 * Use single block read for this HW bug
+				 */
+				if (brq->data.blocks == 2)
+					brq->data.blocks = 1;
+			} else {
+				brq->data.blocks = 1;
+			}
+		}
 	}
 
 	if (brq->data.blocks > 1 || do_rel_wr) {
diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index 18cf462..90b1ee2 100644
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -55,7 +55,7 @@  static const struct sh_mobile_sdhi_of_data of_rcar_gen1_compatible = {
 static const struct sh_mobile_sdhi_of_data of_rcar_gen2_compatible = {
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
-	.capabilities2	= MMC_CAP2_NO_MULTI_READ,
+	.capabilities2	= MMC_CAP2_NO_2BLKS_READ,
 };
 
 static const struct of_device_id sh_mobile_sdhi_of_match[] = {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 7960424..3510fba 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -266,6 +266,9 @@  struct mmc_host {
 #define MMC_CAP2_BOOTPART_NOACC	(1 << 0)	/* Boot partition no access */
 #define MMC_CAP2_FULL_PWR_CYCLE	(1 << 2)	/* Can do full power cycle */
 #define MMC_CAP2_NO_MULTI_READ	(1 << 3)	/* Multiblock reads don't work */
+#define MMC_CAP2_2BLKS_LIMIT	(1 << 4)	/* 2 blocks limit for multi read */
+#define MMC_CAP2_NO_2BLKS_READ	(MMC_CAP2_NO_MULTI_READ | \
+				 MMC_CAP2_2BLKS_LIMIT)
 #define MMC_CAP2_HS200_1_8V_SDR	(1 << 5)        /* can support */
 #define MMC_CAP2_HS200_1_2V_SDR	(1 << 6)        /* can support */
 #define MMC_CAP2_HS200		(MMC_CAP2_HS200_1_8V_SDR | \