Hi Rouven, > > Hello Hadar, > > On Sun, 2020-03-22 at 17:31 +0200, Hadar Gat wrote: > > Introduce low level Arm CryptoCell TRNG HW support. > > > > Signed-off-by: Hadar Gat <hadar.gat@xxxxxxx> > > --- > > drivers/char/hw_random/Kconfig | 12 + > > drivers/char/hw_random/Makefile | 1 + > > drivers/char/hw_random/cctrng.c | 735 > > ++++++++++++++++++++++++++++++++++++++++ > > drivers/char/hw_random/cctrng.h | 69 ++++ > > 4 files changed, 817 insertions(+) > > create mode 100644 drivers/char/hw_random/cctrng.c create mode > > 100644 drivers/char/hw_random/cctrng.h > > > > [...] > > +static int cctrng_probe(struct platform_device *pdev) { > > + struct resource *req_mem_cc_regs = NULL; > > + struct cctrng_drvdata *drvdata; > > + struct device *dev = &pdev->dev; > > + int rc = 0; > > + u32 val; > > + int irq; > > + > > + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); > > + if (!drvdata) > > + return -ENOMEM; > > + > > + drvdata->rng.name = devm_kstrdup(dev, dev_name(dev), > > GFP_KERNEL); > > + if (!drvdata->rng.name) > > + return -ENOMEM; > > + > > + drvdata->rng.read = cctrng_read; > > + drvdata->rng.priv = (unsigned long)drvdata; > > You are not initializing drvdata->rng.quality to a default value, which results in > the TRNG not being used by the kernel by default. If its a perfect TRNG this > should be set to 1024, i.e. 1024 bits of entropy per > 1024 bits of input. Thanks for noticing. I'll fix that. > > Regards, > Rouven Czerwinski Thanks, Hadar