[PATCH v3 0/3] Prevent races when doing read-modify-write of INTMASK

[PATCH v3 0/3] Prevent races when doing read-modify-write of INTMASK

[Doug Anderson]

Bing Zhao at Marvell discovered a race in the way that dw_mmc was
doing a read-modify-write of the INTMASK register.  This 2-patch
series attempts to fix the problem using a simple spinlock.  In order
to do so cleanly, we include a patch to tidy up the way that we
disable low power mode when using SDIO interrupts.

This patch series was not tested on ToT Linux other than basic
compiling and booting, since we don't have the whole Marvell SDIO
stack up and running in mainline yet.  This series is based on
mmc-next (e76b855 mmc: sdhci-esdhc-imx: set actual_clock in clock
setting) merged atop mainlinx Linux.

Changes in v3:
- Add fixup to pandora_wl1251_init_card().

Changes in v2:
- Core patch new for this version.
- Fixed "|" to "&".
- intmask_lock renamed to irq_lock

Doug Anderson (3):
  mmc: core: Support the optional init_card() callback for MMC and SD
  mmc: dw_mmc: Cleanup disable of low power mode w/ SDIO interrupts
  mmc: dw_mmc: Protect read-modify-write of INTMASK with a lock

 arch/arm/mach-omap2/board-omap3pandora.c | 14 +++---
 drivers/mmc/core/mmc.c                   |  6 +++
 drivers/mmc/core/sd.c                    |  7 ++-
 drivers/mmc/host/dw_mmc.c                | 79 +++++++++++++++++++-------------
 drivers/mmc/host/dw_mmc.h                |  1 +
 include/linux/mmc/dw_mmc.h               |  6 +++
 6 files changed, 74 insertions(+), 39 deletions(-)

-- 
1.8.4

[PATCH v3 1/3] mmc: core: Support the optional init_card() callback for MMC and SD

[Doug Anderson]

In (3fcb027 ARM: MXC: mxcmmc: work around a bug in the SDHC busy line
handling) the optional init_card() callback was added.  According to
the original change it was "for now only called from
mmc_sdio_init_card()".

This callback really ought to be called from the SD and MMC init
functions as well.  One current user of this callback
(mxcmci_init_card) will not work as expected if you insert an SDIO
card, then eject it and put a normal SD card in.  Specifically the
normal SD card will not get to run with 4-bit data.

I'd like to use the init_card() callback to handle a similar quirk on
dw_mmc when using SDIO Interrupts (the "low power" feature of the card
needs to be disabled), so that will add a second user of the function.

As part of this change fixup the one place that relied on the callback
only happening for SDIO cards.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Grant Grundler <grundler@chromium.org>
---
Changes in v3:
- Add fixup to pandora_wl1251_init_card().

Changes in v2:
- New for this version.

 arch/arm/mach-omap2/board-omap3pandora.c | 14 ++++++++------
 drivers/mmc/core/mmc.c                   |  6 ++++++
 drivers/mmc/core/sd.c                    |  7 ++++++-
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-omap2/board-omap3pandora.c b/arch/arm/mach-omap2/board-omap3pandora.c
index de1bc6b..6404595 100644
--- a/arch/arm/mach-omap2/board-omap3pandora.c
+++ b/arch/arm/mach-omap2/board-omap3pandora.c
@@ -254,12 +254,14 @@ static void pandora_wl1251_init_card(struct mmc_card *card)
 	 * We have TI wl1251 attached to MMC3. Pass this information to
 	 * SDIO core because it can't be probed by normal methods.
 	 */
-	card->quirks |= MMC_QUIRK_NONSTD_SDIO;
-	card->cccr.wide_bus = 1;
-	card->cis.vendor = 0x104c;
-	card->cis.device = 0x9066;
-	card->cis.blksize = 512;
-	card->cis.max_dtr = 20000000;
+	if (card->type == MMC_TYPE_SDIO || card->type == MMC_TYPE_SD_COMBO) {
+		card->quirks |= MMC_QUIRK_NONSTD_SDIO;
+		card->cccr.wide_bus = 1;
+		card->cis.vendor = 0x104c;
+		card->cis.device = 0x9066;
+		card->cis.blksize = 512;
+		card->cis.max_dtr = 20000000;
+	}
 }
 
 static struct omap2_hsmmc_info omap3pandora_mmc[] = {
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 6d02012..7ad75c0 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -940,6 +940,12 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * Call the optional HC's init_card function to handle quirks.
+	 */
+	if (host->ops->init_card)
+		host->ops->init_card(host, card);
+
+	/*
 	 * For native busses:  set card RCA and quit open drain mode.
 	 */
 	if (!mmc_host_is_spi(host)) {
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 5e8823d..59e2318 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -940,6 +940,12 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * Call the optional HC's init_card function to handle quirks.
+	 */
+	if (host->ops->init_card)
+		host->ops->init_card(host, card);
+
+	/*
 	 * For native busses:  get card RCA and quit open drain mode.
 	 */
 	if (!mmc_host_is_spi(host)) {
@@ -1286,4 +1292,3 @@ err:
 
 	return err;
 }
-
-- 
1.8.4