+
+
+/**
+ * rtc_from4_errstat - perform additional error status checks
+ * @mtd: MTD device structure
+ * @this: NAND chip structure
+ * @state: state or the operation
+ * @status: status code returned from read status
+ * @page: startpage inside the chip, must be called with (page & this->pagemask)
+ *
+ * Perform additional error status checks on erase and write failures
+ * to determine if errors are correctable. For this device, correctable
+ * 1-bit errors on erase and write are considered acceptable.
+ *
+ * note: see pages 34..37 of data sheet for details.
+ *
+ */
+static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this, int state, int status, int page)
+{
+ int er_stat=0;
+ int rtn, retlen;
+ size_t len;
+ uint8_t *buf;
+ int i;
+
+ this->cmdfunc (mtd, NAND_CMD_STATUS_CLEAR, -1, -1);
+
+ if (state == FL_ERASING) {
+ for (i=0; i<4; i++) {
+ if (status & 1<<(i+1)) {
+ this->cmdfunc (mtd, (NAND_CMD_STATUS_ERROR + i + 1), -1, -1);
+ rtn = this->read_byte(mtd);
+ this->cmdfunc (mtd, NAND_CMD_STATUS_RESET, -1, -1);
+ if (!(rtn & ERR_STAT_ECC_AVAILABLE)) {
+ er_stat |= 1<<(i+1); /* err_ecc_not_avail */
+ }
+ }
+ }
+ } else if (state == FL_WRITING) {
+ /* single bank write logic */
+ this->cmdfunc (mtd, NAND_CMD_STATUS_ERROR, -1, -1);
+ rtn = this->read_byte(mtd);
+ this->cmdfunc (mtd, NAND_CMD_STATUS_RESET, -1, -1);
+ if (!(rtn & ERR_STAT_ECC_AVAILABLE)) {
+ er_stat |= 1<<1; /* err_ecc_not_avail */
+ } else {
+ len = mtd->oobblock;
+ buf = kmalloc (len, GFP_KERNEL);
+ if (!buf) {
+ printk (KERN_ERR "rtc_from4_errstat: Out of memory!\n");
+ er_stat = 1; /* if we can't check, assume failed */
+ } else {
+ /* recovery read */
+ /* page read */
+ rtn = nand_do_read_ecc (mtd, page, len, &retlen, buf, NULL, this->autooob, 1);
+ if (rtn) { /* if read failed or > 1-bit error corrected */
+ er_stat |= 1<<1; /* ECC read failed */
+ }
+ kfree(buf);
+ }
+ }
+ }
+
+ rtn = status;
+ if (er_stat == 0) { /* if ECC is available */
+ rtn = (status & ~NAND_STATUS_FAIL); /* clear the error bit */
+ }
+
+ return rtn;
+}