Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=55556da01284af8c2174b786b3eca8e11301b656
Commit:     55556da01284af8c2174b786b3eca8e11301b656
Parent:     4be34c99a2f3aa90fa42e62c0918f07afb8a645b
Author:     Philip Langdale <[EMAIL PROTECTED]>
AuthorDate: Fri Mar 16 19:39:00 2007 -0700
Committer:  Pierre Ossman <[EMAIL PROTECTED]>
CommitDate: Tue May 1 14:14:50 2007 +0200

    MMC: Fix handling of low-voltage cards
    
    Fix handling of low voltage MMC cards.
    
    The latest MMC and SD specs both agree that support for
    low-voltage operations is indicated by bit 7 in the OCR.
    The MMC spec states that the low voltage range is
    1.65-1.95V while the SD spec leaves the actual voltage
    range undefined - meaning that there is still no such
    thing as a low voltage SD card.
    
    However, an old Sandisk spec implied that bits 7.0
    represented voltages below 2.0V in 1V or 0.5V increments,
    and the code was accordingly written with that expectation.
    
    This confusion meant that host drivers attempting to support
    the typical low voltage (1.8V) would set the wrong bits in
    the host OCR mask (usually bits 5 and/or 6) resulting in the
    the low voltage mode never being used.
    
    This change corrects the low voltage range and adds sanity
    checks on the reserved bits (0-6) and for SD cards that
    claim to support low-voltage operations.
    
    Signed-off-by: Philip Langdale <[EMAIL PROTECTED]>
    Signed-off-by: Pierre Ossman <[EMAIL PROTECTED]>
---
 drivers/mmc/core/mmc.c   |   11 +++++++++++
 drivers/mmc/core/sd.c    |   18 ++++++++++++++++++
 drivers/mmc/host/sdhci.c |    5 ++---
 include/linux/mmc/host.h |    9 +--------
 4 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index c528017..c2e120b 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -323,6 +323,17 @@ int mmc_attach_mmc(struct mmc_host *host, u32 ocr)
 
        mmc_attach_bus(host, &mmc_ops);
 
+       /*
+        * Sanity check the voltages that the card claims to
+        * support.
+        */
+       if (ocr & 0x7F) {
+               printk(KERN_WARNING "%s: card claims to support voltages "
+                      "below the defined range. These will be ignored.\n",
+                      mmc_hostname(host));
+               ocr &= ~0x7F;
+       }
+
        host->ocr = mmc_select_voltage(host, ocr);
 
        /*
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 6c6beb4..fb18b30 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -297,6 +297,24 @@ int mmc_attach_sd(struct mmc_host *host, u32 ocr)
 
        mmc_attach_bus(host, &mmc_sd_ops);
 
+       /*
+        * Sanity check the voltages that the card claims to
+        * support.
+        */
+       if (ocr & 0x7F) {
+               printk(KERN_WARNING "%s: card claims to support voltages "
+                      "below the defined range. These will be ignored.\n",
+                      mmc_hostname(host));
+               ocr &= ~0x7F;
+       }
+
+       if (ocr & MMC_VDD_165_195) {
+               printk(KERN_WARNING "%s: SD card claims to support the "
+                      "incompletely defined 'low voltage range'. This "
+                      "will be ignored.\n", mmc_hostname(host));
+               ocr &= ~MMC_VDD_165_195;
+       }
+
        host->ocr = mmc_select_voltage(host, ocr);
 
        /*
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a57f6a3..ff5bf73 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -659,8 +659,7 @@ static void sdhci_set_power(struct sdhci_host *host, 
unsigned short power)
        pwr = SDHCI_POWER_ON;
 
        switch (1 << power) {
-       case MMC_VDD_17_18:
-       case MMC_VDD_18_19:
+       case MMC_VDD_165_195:
                pwr |= SDHCI_POWER_180;
                break;
        case MMC_VDD_29_30:
@@ -1280,7 +1279,7 @@ static int __devinit sdhci_probe_slot(struct pci_dev 
*pdev, int slot)
        if (caps & SDHCI_CAN_VDD_300)
                mmc->ocr_avail |= MMC_VDD_29_30|MMC_VDD_30_31;
        if (caps & SDHCI_CAN_VDD_180)
-               mmc->ocr_avail |= MMC_VDD_17_18|MMC_VDD_18_19;
+               mmc->ocr_avail |= MMC_VDD_165_195;
 
        if (mmc->ocr_avail == 0) {
                printk(KERN_ERR "%s: Hardware doesn't report any "
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 5a66d8a..b1350df 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -65,14 +65,7 @@ struct mmc_host {
        unsigned int            f_max;
        u32                     ocr_avail;
 
-#define MMC_VDD_145_150                0x00000001      /* VDD voltage 1.45 - 
1.50 */
-#define MMC_VDD_150_155                0x00000002      /* VDD voltage 1.50 - 
1.55 */
-#define MMC_VDD_155_160                0x00000004      /* VDD voltage 1.55 - 
1.60 */
-#define MMC_VDD_160_165                0x00000008      /* VDD voltage 1.60 - 
1.65 */
-#define MMC_VDD_165_170                0x00000010      /* VDD voltage 1.65 - 
1.70 */
-#define MMC_VDD_17_18          0x00000020      /* VDD voltage 1.7 - 1.8 */
-#define MMC_VDD_18_19          0x00000040      /* VDD voltage 1.8 - 1.9 */
-#define MMC_VDD_19_20          0x00000080      /* VDD voltage 1.9 - 2.0 */
+#define MMC_VDD_165_195                0x00000080      /* VDD voltage 1.65 - 
1.95 */
 #define MMC_VDD_20_21          0x00000100      /* VDD voltage 2.0 ~ 2.1 */
 #define MMC_VDD_21_22          0x00000200      /* VDD voltage 2.1 ~ 2.2 */
 #define MMC_VDD_22_23          0x00000400      /* VDD voltage 2.2 ~ 2.3 */
-
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