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Subject[PATCH 15/39] mtd: nand: denali: improve readability of handle_ecc()
Date
This function is unreadable due to the deep nesting.  Note this
function does a job only when INTR_STATUS__ECC_ERR is set.
So, if the flag is not set, let it bail-out.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

drivers/mtd/nand/denali.c | 119 +++++++++++++++++++++++-----------------------
1 file changed, 59 insertions(+), 60 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index a7dc692..b577560 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -908,69 +908,68 @@ static bool handle_ecc(struct denali_nand_info *denali, u8 *buf,
{
bool check_erased_page = false;
unsigned int bitflips = 0;
+ u32 err_address, err_correction_info, err_byte, err_sector, err_device,
+ err_correction_value;

- if (irq_status & INTR_STATUS__ECC_ERR) {
- /* read the ECC errors. we'll ignore them for now */
- u32 err_address, err_correction_info, err_byte,
- err_sector, err_device, err_correction_value;
- denali_set_intr_modes(denali, false);
-
- do {
- err_address = ioread32(denali->flash_reg +
- ECC_ERROR_ADDRESS);
- err_sector = ECC_SECTOR(err_address);
- err_byte = ECC_BYTE(err_address);
-
- err_correction_info = ioread32(denali->flash_reg +
- ERR_CORRECTION_INFO);
- err_correction_value =
+ if (!(irq_status & INTR_STATUS__ECC_ERR))
+ goto out;
+
+ /* read the ECC errors. we'll ignore them for now */
+ denali_set_intr_modes(denali, false);
+
+ do {
+ err_address = ioread32(denali->flash_reg + ECC_ERROR_ADDRESS);
+ err_sector = ECC_SECTOR(err_address);
+ err_byte = ECC_BYTE(err_address);
+
+ err_correction_info = ioread32(denali->flash_reg +
+ ERR_CORRECTION_INFO);
+ err_correction_value =
ECC_CORRECTION_VALUE(err_correction_info);
- err_device = ECC_ERR_DEVICE(err_correction_info);
-
- if (ECC_ERROR_CORRECTABLE(err_correction_info)) {
- /*
- * If err_byte is larger than ECC_SECTOR_SIZE,
- * means error happened in OOB, so we ignore
- * it. It's no need for us to correct it
- * err_device is represented the NAND error
- * bits are happened in if there are more
- * than one NAND connected.
- */
- if (err_byte < ECC_SECTOR_SIZE) {
- struct mtd_info *mtd =
- nand_to_mtd(&denali->nand);
- int offset;
-
- offset = (err_sector *
- ECC_SECTOR_SIZE +
- err_byte) *
- denali->devnum +
- err_device;
- /* correct the ECC error */
- buf[offset] ^= err_correction_value;
- mtd->ecc_stats.corrected++;
- bitflips++;
- }
- } else {
- /*
- * if the error is not correctable, need to
- * look at the page to see if it is an erased
- * page. if so, then it's not a real ECC error
- */
- check_erased_page = true;
+ err_device = ECC_ERR_DEVICE(err_correction_info);
+
+ if (ECC_ERROR_CORRECTABLE(err_correction_info)) {
+ /*
+ * If err_byte is larger than ECC_SECTOR_SIZE, means error
+ * happened in OOB, so we ignore it. It's no need for
+ * us to correct it err_device is represented the NAND
+ * error bits are happened in if there are more than
+ * one NAND connected.
+ */
+ if (err_byte < ECC_SECTOR_SIZE) {
+ struct mtd_info *mtd =
+ nand_to_mtd(&denali->nand);
+ int offset;
+
+ offset = (err_sector * ECC_SECTOR_SIZE + err_byte) *
+ denali->devnum + err_device;
+ /* correct the ECC error */
+ buf[offset] ^= err_correction_value;
+ mtd->ecc_stats.corrected++;
+ bitflips++;
}
- } while (!ECC_LAST_ERR(err_correction_info));
- /*
- * Once handle all ecc errors, controller will triger
- * a ECC_TRANSACTION_DONE interrupt, so here just wait
- * for a while for this interrupt
- */
- while (!(read_interrupt_status(denali) &
- INTR_STATUS__ECC_TRANSACTION_DONE))
- cpu_relax();
- clear_interrupts(denali);
- denali_set_intr_modes(denali, true);
- }
+ } else {
+ /*
+ * if the error is not correctable, need to look at the
+ * page to see if it is an erased page. if so, then
+ * it's not a real ECC error
+ */
+ check_erased_page = true;
+ }
+ } while (!ECC_LAST_ERR(err_correction_info));
+
+ /*
+ * Once handle all ecc errors, controller will triger a
+ * ECC_TRANSACTION_DONE interrupt, so here just wait for
+ * a while for this interrupt
+ */
+ while (!(read_interrupt_status(denali) &
+ INTR_STATUS__ECC_TRANSACTION_DONE))
+ cpu_relax();
+ clear_interrupts(denali);
+ denali_set_intr_modes(denali, true);
+
+ out:
*max_bitflips = bitflips;
return check_erased_page;
}
--
2.7.4
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