[PATCH v4 2/2] mtd: nand: raw: brcmnand: When oops in progress use pio and interrupt polling

From: Kamal Dasu
Date: Tue Jun 18 2019 - 14:32:35 EST


If mtd_oops is in progress, switch to polling during NAND command
completion instead of relying on DMA/interrupts so that the mtd_oops
buffer can be completely written in the assigned NAND partition.

Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
---
drivers/mtd/nand/raw/brcmnand/brcmnand.c | 48 ++++++++++++++++++++++++++++++--
1 file changed, 45 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index 8735277..27b22d6 100644
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -151,6 +151,7 @@ struct brcmnand_controller {
u32 nand_cs_nand_xor;
u32 corr_stat_threshold;
u32 flash_dma_mode;
+ bool pio_poll_mode;
};

struct brcmnand_cfg {
@@ -815,6 +816,20 @@ static inline bool has_flash_dma(struct brcmnand_controller *ctrl)
return ctrl->flash_dma_base;
}

+static inline void disable_ctrl_irqs(struct brcmnand_controller *ctrl)
+{
+ if (ctrl->pio_poll_mode)
+ return;
+
+ if (has_flash_dma(ctrl)) {
+ ctrl->flash_dma_base = 0;
+ disable_irq(ctrl->dma_irq);
+ }
+
+ disable_irq(ctrl->irq);
+ ctrl->pio_poll_mode = true;
+}
+
static inline bool flash_dma_buf_ok(const void *buf)
{
return buf && !is_vmalloc_addr(buf) &&
@@ -1229,15 +1244,42 @@ static void brcmnand_cmd_ctrl(struct nand_chip *chip, int dat,
/* intentionally left blank */
}

+static bool brcmstb_nand_wait_for_completion(struct nand_chip *chip)
+{
+ struct brcmnand_host *host = nand_get_controller_data(chip);
+ struct brcmnand_controller *ctrl = host->ctrl;
+ struct mtd_info *mtd = nand_to_mtd(chip);
+ bool err = false;
+ int sts;
+
+ if (mtd->panic_write_triggered) {
+ /* switch to interrupt polling and PIO mode */
+ disable_ctrl_irqs(ctrl);
+ sts = bcmnand_ctrl_poll_status(ctrl, NAND_CTRL_RDY,
+ NAND_CTRL_RDY, 0);
+ err = (sts < 0) ? true : false;
+ } else {
+ unsigned long timeo = msecs_to_jiffies(
+ NAND_POLL_STATUS_TIMEOUT_MS);
+ /* wait for completion interrupt */
+ sts = wait_for_completion_timeout(&ctrl->done, timeo);
+ err = (sts <= 0) ? true : false;
+ }
+
+ return err;
+}
+
static int brcmnand_waitfunc(struct nand_chip *chip)
{
struct brcmnand_host *host = nand_get_controller_data(chip);
struct brcmnand_controller *ctrl = host->ctrl;
- unsigned long timeo = msecs_to_jiffies(100);
+ bool err = false;

dev_dbg(ctrl->dev, "wait on native cmd %d\n", ctrl->cmd_pending);
- if (ctrl->cmd_pending &&
- wait_for_completion_timeout(&ctrl->done, timeo) <= 0) {
+ if (ctrl->cmd_pending)
+ err = brcmstb_nand_wait_for_completion(chip);
+
+ if (err) {
u32 cmd = brcmnand_read_reg(ctrl, BRCMNAND_CMD_START)
>> brcmnand_cmd_shift(ctrl);

--
1.9.0.138.g2de3478