Currently there is no error checking for raw read. For raw
reads, there won’t be any ECC failure but the operational
failures are possible, so schedule the NAND_FLASH_STATUS read
after each codeword.

Acked-by: Miquel Raynal <miquel.ray...@bootlin.com>
Signed-off-by: Abhishek Sahu <abs...@codeaurora.org>
---
* Changes from v3:
 1. Since bad block reorganization patch has removed from this
    patch series so following change is required in copy_last_cw)
    config_nand_single_cw_page_read(nandc);
    -> config_nand_single_cw_page_read(nandc, host->use_ecc);

* Changes from v2:
  NONE

* Changes from v1:
 1. Removed the code for copy_last_cw.

 drivers/mtd/nand/raw/qcom_nandc.c | 58 +++++++++++++++++++++++++++------------
 1 file changed, 40 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/nand/raw/qcom_nandc.c 
b/drivers/mtd/nand/raw/qcom_nandc.c
index 887b1f6..5999c39 100644
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -1096,7 +1096,8 @@ static void config_nand_page_read(struct 
qcom_nand_controller *nandc)
  * Helper to prepare DMA descriptors for configuring registers
  * before reading each codeword in NAND page.
  */
-static void config_nand_cw_read(struct qcom_nand_controller *nandc)
+static void
+config_nand_cw_read(struct qcom_nand_controller *nandc, bool use_ecc)
 {
        if (nandc->props->is_bam)
                write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
@@ -1105,19 +1106,25 @@ static void config_nand_cw_read(struct 
qcom_nand_controller *nandc)
        write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
        write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
 
-       read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
-       read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
-                    NAND_BAM_NEXT_SGL);
+       if (use_ecc) {
+               read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
+               read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
+                            NAND_BAM_NEXT_SGL);
+       } else {
+               read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
+       }
 }
 
 /*
  * Helper to prepare dma descriptors to configure registers needed for reading 
a
  * single codeword in page
  */
-static void config_nand_single_cw_page_read(struct qcom_nand_controller *nandc)
+static void
+config_nand_single_cw_page_read(struct qcom_nand_controller *nandc,
+                               bool use_ecc)
 {
        config_nand_page_read(nandc);
-       config_nand_cw_read(nandc);
+       config_nand_cw_read(nandc, use_ecc);
 }
 
 /*
@@ -1198,7 +1205,7 @@ static int nandc_param(struct qcom_nand_host *host)
        nandc->buf_count = 512;
        memset(nandc->data_buffer, 0xff, nandc->buf_count);
 
-       config_nand_single_cw_page_read(nandc);
+       config_nand_single_cw_page_read(nandc, false);
 
        read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
                      nandc->buf_count, 0);
@@ -1563,6 +1570,23 @@ struct read_stats {
        __le32 erased_cw;
 };
 
+/* reads back FLASH_STATUS register set by the controller */
+static int check_flash_errors(struct qcom_nand_host *host, int cw_cnt)
+{
+       struct nand_chip *chip = &host->chip;
+       struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+       int i;
+
+       for (i = 0; i < cw_cnt; i++) {
+               u32 flash = le32_to_cpu(nandc->reg_read_buf[i]);
+
+               if (flash & (FS_OP_ERR | FS_MPU_ERR))
+                       return -EIO;
+       }
+
+       return 0;
+}
+
 /*
  * reads back status registers set by the controller to notify page read
  * errors. this is equivalent to what 'ecc->correct()' would do.
@@ -1729,7 +1753,7 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 
*data_buf,
                        }
                }
 
-               config_nand_cw_read(nandc);
+               config_nand_cw_read(nandc, true);
 
                if (data_buf)
                        read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
@@ -1791,7 +1815,7 @@ static int copy_last_cw(struct qcom_nand_host *host, int 
page)
        set_address(host, host->cw_size * (ecc->steps - 1), page);
        update_rw_regs(host, 1, true);
 
-       config_nand_single_cw_page_read(nandc);
+       config_nand_single_cw_page_read(nandc, host->use_ecc);
 
        read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size, 0);
 
@@ -1874,7 +1898,7 @@ static int qcom_nandc_read_page_raw(struct mtd_info *mtd,
                        nandc_set_read_loc(nandc, 3, read_loc, oob_size2, 1);
                }
 
-               config_nand_cw_read(nandc);
+               config_nand_cw_read(nandc, false);
 
                read_data_dma(nandc, reg_off, data_buf, data_size1, 0);
                reg_off += data_size1;
@@ -1893,12 +1917,13 @@ static int qcom_nandc_read_page_raw(struct mtd_info 
*mtd,
        }
 
        ret = submit_descs(nandc);
-       if (ret)
+       free_descs(nandc);
+       if (ret) {
                dev_err(nandc->dev, "failure to read raw page\n");
+               return ret;
+       }
 
-       free_descs(nandc);
-
-       return ret;
+       return check_flash_errors(host, ecc->steps);
 }
 
 /* implements ecc->read_oob() */
@@ -2117,7 +2142,6 @@ static int qcom_nandc_block_bad(struct mtd_info *mtd, 
loff_t ofs)
        struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
        struct nand_ecc_ctrl *ecc = &chip->ecc;
        int page, ret, bbpos, bad = 0;
-       u32 flash_status;
 
        page = (int)(ofs >> chip->page_shift) & chip->pagemask;
 
@@ -2134,9 +2158,7 @@ static int qcom_nandc_block_bad(struct mtd_info *mtd, 
loff_t ofs)
        if (ret)
                goto err;
 
-       flash_status = le32_to_cpu(nandc->reg_read_buf[0]);
-
-       if (flash_status & (FS_OP_ERR | FS_MPU_ERR)) {
+       if (check_flash_errors(host, 1)) {
                dev_warn(nandc->dev, "error when trying to read BBM\n");
                goto err;
        }
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc.
is a member of Code Aurora Forum, hosted by The Linux Foundation

Reply via email to