@@ -166,34 +166,29 @@ static irqreturn_t imx_rngc_irq(int irq, void *priv)
static int imx_rngc_init(struct hwrng *rng)
{
struct imx_rngc *rngc = container_of(rng, struct imx_rngc, rng);
- u32 cmd, ctrl;
+ u32 cmd, ctrl, status, err_reg;
int ret;
/* clear error */
cmd = readl(rngc->base + RNGC_COMMAND);
writel(cmd | RNGC_CMD_CLR_ERR, rngc->base + RNGC_COMMAND);
- imx_rngc_irq_unmask(rngc);
-
/* create seed, repeat while there is some statistical error */
do {
/* seed creation */
cmd = readl(rngc->base + RNGC_COMMAND);
writel(cmd | RNGC_CMD_SEED, rngc->base + RNGC_COMMAND);
- ret = wait_for_completion_timeout(&rngc->rng_op_done,
- usecs_to_jiffies(RNGC_SEED_TIMEOUT));
- if (!ret) {
- ret = -ETIMEDOUT;
- goto err;
- }
+ ret = readl_poll_timeout(rngc->base + RNGC_STATUS, status,
+ status & RNGC_STATUS_SEED_DONE, 20000, RNGC_SEED_TIMEOUT);
+ if (ret < 0)
+ return ret;
- } while (rngc->err_reg == RNGC_ERROR_STATUS_STAT_ERR);
+ err_reg = readl(rngc->base + RNGC_ERROR);
+ } while (err_reg == RNGC_ERROR_STATUS_STAT_ERR);
- if (rngc->err_reg) {
- ret = -EIO;
- goto err;
- }
+ if (err_reg)
+ return -EIO;
/*
* enable automatic seeding, the rngc creates a new seed automatically
@@ -209,10 +204,6 @@ static int imx_rngc_init(struct hwrng *rng)
* we mask the interrupt ourselves if we return an error
*/
return 0;
-
-err:
- imx_rngc_irq_mask_clear(rngc);
- return ret;
}
static void imx_rngc_cleanup(struct hwrng *rng)
Use polling instead of interrupt + completion to wait until the initial seed was calculated. This should take about 30ms. Call readl_poll_timeout and set the poll interval to the recommended maximum of 20ms. readl_poll_timeout uses usleep_range, this is based on a hrtimer. The task will we put to sleep while waiting, this does not burn CPU cycles by waiting in the foreground. Signed-off-by: Martin Kaiser <martin@kaiser.cx> --- v2: - use shorter timeout and polling interval - readl_poll_timeout does not wait in the foreground drivers/char/hw_random/imx-rngc.c | 27 +++++++++------------------ 1 file changed, 9 insertions(+), 18 deletions(-)