Re: [PATCH] mtd: sh_flctl: Switch from tick-based to time-based timeout

Bastian Hecht
2012-07-25T15:22:04Z

Hello Artem!

Could you please pull out this patch of your tree? While reworking the
driver for IRQ-driven use, I've realized that this conversion makes no
sense as all loops use a udelay(1) in them. So the timeout is already
time based.

Sorry for the inconvenience,

Bastian Hecht

2012/7/4 Bastian Hecht <hechtb@googlemail.com>:
> Instead of counting down a compile-time value, we use a value based on
> jiffies.
>
> Signed-off-by: Bastian Hecht <hechtb@gmail.com>
> ---
> Artem mentioned the idea a while ago - here is the simple implementation now.
>
> drivers/mtd/nand/sh_flctl.c | 14 +++++++++-----
> include/linux/mtd/sh_flctl.h | 2 +-
> 2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mtd/nand/sh_flctl.c b/drivers/mtd/nand/sh_flctl.c
> index ed03ed2..0d9cce7 100644
> --- a/drivers/mtd/nand/sh_flctl.c
> +++ b/drivers/mtd/nand/sh_flctl.c
> @@ -73,6 +73,8 @@ static struct nand_bbt_descr flctl_4secc_largepage = {
> .pattern = scan_ff_pattern,
> };
>
> +static int loop_timeout_max;
> +
> static void empty_fifo(struct sh_flctl *flctl)
> {
> writel(flctl->flintdmacr_base | AC1CLR | AC0CLR, FLINTDMACR(flctl));
> @@ -91,7 +93,7 @@ static void timeout_error(struct sh_flctl *flctl, const char *str)
>
> static void wait_completion(struct sh_flctl *flctl)
> {
> - uint32_t timeout = LOOP_TIMEOUT_MAX;
> + uint32_t timeout = loop_timeout_max;
>
> while (timeout--) {
> if (readb(FLTRCR(flctl)) & TREND) {
> @@ -138,7 +140,7 @@ static void set_addr(struct mtd_info *mtd, int column, int page_addr)
>
> static void wait_rfifo_ready(struct sh_flctl *flctl)
> {
> - uint32_t timeout = LOOP_TIMEOUT_MAX;
> + uint32_t timeout = loop_timeout_max;
>
> while (timeout--) {
> uint32_t val;
> @@ -153,7 +155,7 @@ static void wait_rfifo_ready(struct sh_flctl *flctl)
>
> static void wait_wfifo_ready(struct sh_flctl *flctl)
> {
> - uint32_t len, timeout = LOOP_TIMEOUT_MAX;
> + uint32_t len, timeout = loop_timeout_max;
>
> while (timeout--) {
> /* check FIFO */
> @@ -168,7 +170,7 @@ static void wait_wfifo_ready(struct sh_flctl *flctl)
> static enum flctl_ecc_res_t wait_recfifo_ready
> (struct sh_flctl *flctl, int sector_number)
> {
> - uint32_t timeout = LOOP_TIMEOUT_MAX;
> + uint32_t timeout = loop_timeout_max;
> void __iomem *ecc_reg[4];
> int i;
> int state = FL_SUCCESS;
> @@ -247,7 +249,7 @@ static enum flctl_ecc_res_t wait_recfifo_ready
>
> static void wait_wecfifo_ready(struct sh_flctl *flctl)
> {
> - uint32_t timeout = LOOP_TIMEOUT_MAX;
> + uint32_t timeout = loop_timeout_max;
> uint32_t len;
>
> while (timeout--) {
> @@ -939,6 +941,8 @@ static int __devinit flctl_probe(struct platform_device *pdev)
> pm_runtime_enable(&pdev->dev);
> pm_runtime_resume(&pdev->dev);
>
> + loop_timeout_max = loops_per_jiffy * msecs_to_jiffies(LOOP_TIMEOUT_MS);
> +
> ret = nand_scan_ident(flctl_mtd, 1, NULL);
> if (ret)
> goto err_chip;
> diff --git a/include/linux/mtd/sh_flctl.h b/include/linux/mtd/sh_flctl.h
> index 01e4b15..ade44c1 100644
> --- a/include/linux/mtd/sh_flctl.h
> +++ b/include/linux/mtd/sh_flctl.h
> @@ -129,7 +129,7 @@
> #define _4ECCEND (0x1 << 1) /* 4 symbols end */
> #define _4ECCEXST (0x1 << 0) /* 4 symbols exist */
>
> -#define LOOP_TIMEOUT_MAX 0x00010000
> +#define LOOP_TIMEOUT_MS 100
>
> enum flctl_ecc_res_t {
> FL_SUCCESS,
> --
> 1.7.9.5
>