Messages in this thread | | | Date | Fri, 6 Jan 2023 16:39:24 +0800 | From | Herbert Xu <> | Subject | Re: [PATCH v2 2/3] hwrng: starfive - Add TRNG driver for StarFive SoC |
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On Wed, Dec 28, 2022 at 03:11:02PM +0800, Jia Jie Ho wrote: > > +static int starfive_trng_cmd(struct starfive_trng *trng, u32 cmd) > +{ > + int ret; > + > + ret = starfive_trng_wait_idle(trng); > + if (ret) > + return -ETIMEDOUT; > + > + switch (cmd) { > + case STARFIVE_CTRL_EXEC_NOP: > + writel(cmd, trng->base + STARFIVE_CTRL); > + break; > + case STARFIVE_CTRL_GENE_RANDNUM: > + reinit_completion(&trng->random_done); > + writel(cmd, trng->base + STARFIVE_CTRL); > + ret = wait_for_completion_timeout(&trng->random_done, 3000);
Please don't use a constant jiffies value, because it may vary in length. Instead use a constant millisecond value and convert it to jiffies.
> +static irqreturn_t starfive_trng_irq(int irq, void *priv) > +{ > + u32 status; > + struct starfive_trng *trng = (struct starfive_trng *)priv; > + > + status = readl(trng->base + STARFIVE_ISTAT); > + if (status & STARFIVE_ISTAT_RAND_RDY) { > + writel(STARFIVE_ISTAT_RAND_RDY, trng->base + STARFIVE_ISTAT); > + complete(&trng->random_done); > + } > + > + if (status & STARFIVE_ISTAT_SEED_DONE) { > + writel(STARFIVE_ISTAT_SEED_DONE, trng->base + STARFIVE_ISTAT); > + complete(&trng->reseed_done); > + } > + > + if (status & STARFIVE_ISTAT_LFSR_LOCKUP) { > + writel(STARFIVE_ISTAT_LFSR_LOCKUP, trng->base + STARFIVE_ISTAT); > + starfive_trng_cmd(trng, STARFIVE_CTRL_EXEC_RANDRESEED);
You should not sleep in an IRQ handler.
> +static int starfive_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
You should respect the wait argument and not do polling/sleeping if it is false.
Cheers, -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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