From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomas Melin Date: Wed, 23 Nov 2016 15:04:58 +0200 Subject: [U-Boot] [RFC PATCH 1/1] Read mmc device memory capacity from EXT_CSD if memory is addressed by sector Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi, We have successfully been using this patch to fix the problem mentioned in the original message. Could this be picked up upstream? BR, Tomas On Wed Feb 5 21:00:42 CET 2014, Frank Bormann wrote: >Hello Everyone, > >I believe, there is a bug in the mmc driver code pertaining to how u-boot >detects memory size of an mmc device. However, I am not 100% sure, my solution >conforms to the JEDEC standard. So I am putting it up for discussion. > >Previously, sector count indicated by mmc devices in the EXT_CSD >would only be used in u-boot if the size indicated is greater than >2 GB. This seems to be incorrect. I am working with a 4 GB Micron >eMMC device that after partition configuration and setting the >user data area to enhanced mode has a remaining capacity of less >than 2 GB for the user data area. JESD84-B50 explicitly states in >6.2.4 that for these devices SEC_CNT from the EXT_CSD is still >valid even if the memory size for that device has dropped below >2 GB by the partition configuration applied. The access mode bits >from the OCR register seem to provide a better way to decide >whether to use the CSD-based C_SIZE & C_MULT or the EXT_CSD-based >SEC_CNT information when determining the device's capacity. > >In particular, this fixes a bug where u-boot SPL would assign 0 to >mmc->block_dev.lba later on in the mmc_startup() function and >subsequently fail to load u-boot from that mmc due to the original >C_SIZE & C_MULT code assigning a 4 TB size to mmc->capacity, that >incorrect capacity never being overwritten by the SEC_CNT capacity >calculation (due to its size being less than 2 GB) and then finally >lldiv(mmc->capacity, mmc->read_bl_len) exceeding the 32-bit result >data type of mmc->block_dev.lba. > >Signed-off-by: Frank Bormann >--- > drivers/mmc/mmc.c | 10 +++++----- > include/mmc.h | 1 + > 2 files changed, 6 insertions(+), 5 deletions(-) > >diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c >index c6a1c23..c5d1efc 100644 >--- a/drivers/mmc/mmc.c >+++ b/drivers/mmc/mmc.c >@@ -935,19 +935,19 @@ static int mmc_startup(struct mmc *mmc) > if (!IS_SD(mmc) && (mmc->version >= MMC_VERSION_4)) { > /* check ext_csd version and capacity */ > err = mmc_send_ext_csd(mmc, ext_csd); >- if (!err && (ext_csd[EXT_CSD_REV] >= 2)) { >+ if (!err && (ext_csd[EXT_CSD_REV] >= 2) && >+ (mmc->ocr & OCR_ACCESS_MODE) == OCR_ACCESS_BY_SECTOR) { > /* > * According to the JEDEC Standard, the value of >- * ext_csd's capacity is valid if the value is more >- * than 2GB >+ * ext_csd's capacity is valid if the device addresses >+ * its memory by sector > */ > capacity = ext_csd[EXT_CSD_SEC_CNT] << 0 > | ext_csd[EXT_CSD_SEC_CNT + 1] << 8 > | ext_csd[EXT_CSD_SEC_CNT + 2] << 16 > | ext_csd[EXT_CSD_SEC_CNT + 3] << 24; > capacity *= MMC_MAX_BLOCK_LEN; >- if ((capacity >> 20) > 2 * 1024) >- mmc->capacity_user = capacity; >+ mmc->capacity_user = capacity; > } > > switch (ext_csd[EXT_CSD_REV]) { >diff --git a/include/mmc.h b/include/mmc.h >index e1060b9..816b580 100644 >--- a/include/mmc.h >+++ b/include/mmc.h >@@ -104,6 +104,7 @@ > #define OCR_HCS 0x40000000 > #define OCR_VOLTAGE_MASK 0x007FFF80 > #define OCR_ACCESS_MODE 0x60000000 >+#define OCR_ACCESS_BY_SECTOR (1 << 30) > > #define SECURE_ERASE 0x80000000