On Sun, 19 Apr 2020 at 08:33, Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> wrote: > > > > -----Original Message----- > > > From: Pavel Machek <pavel@xxxxxx> > > > Sent: Saturday, 18 April 2020 13:44 > > > To: kernel list <linux-kernel@xxxxxxxxxxxxxxx>; Hadar Gat > > > <Hadar.Gat@xxxxxxx>; herbert@xxxxxxxxxxxxxxxxxxx > > > Subject: Arm CryptoCell driver -- default Y, even on machines where it is > > > obviously useless > > > > > > Hi! > > > > > > I'm configuring kernel for x86, and I get offered HW_RANDOM_CCTRNG with > > > default=Y, and help text suggesting I should enable it. > > > > > > That's... two wrong suggestions, right? > > > > > > Best regards, > > > Pavel > ... > > ________________________________________ > > From: Hadar Gat <Hadar.Gat@xxxxxxx> > > Sent: Saturday, April 18, 2020 11:31 PM > > To: Pavel Machek; kernel list; herbert@xxxxxxxxxxxxxxxxxxx > > Cc: Ofir Drang; Gilad Ben Yossef; nd > > Subject: RE: Arm CryptoCell driver -- default Y, even on machines where it is obviously useless > > > > Hi Pavel, > > I think you got it right.. > > Indeed, Arm CryptoCell CCTRNG driver couldn't be used and obviously useless if the Arm CryptoCell HW does not exist in the system. > > There's a delicate point here though - CryptoCell is an independent > hardware block, it is not tied to a particular CPU architecture. > There are SoCs with none-Arm architecture CPU using it. > > So I would say whatever the answer is, it should be the same for any > generic embedded style HW block. > > And the help text is not architecture specific anyway, is it not..? > Both the default y and and the help text are indeed incorrect. This should be fixed. We don't enable device drivers by default, and definitely not as as builtins. A conditional default m could be acceptable if the condition is sufficiently narrow. While at it, could we add a depends on CONFIG_OF since this code is definitely unusable on non-DT systems.
