lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Fri, 18 Dec 2020 20:44:14 +0000
From:   Mark Brown <>
To:     Pratyush Yadav <>
Cc:     Sowjanya Komatineni <>,
        Boris Brezillon <>,,,,,,,,,,
Subject: Re: [PATCH v4 5/9] spi: spi-mem: Mark dummy transfers by setting
 dummy_data bit

On Fri, Dec 18, 2020 at 08:41:02PM +0000, Mark Brown wrote:
> On Sat, Dec 19, 2020 at 12:49:38AM +0530, Pratyush Yadav wrote:

> > Anyway, if the SPI maintainers think this is worth it, I won't object.

> This gets kind of circular, for me it's a question of if there's some
> meaningful benefit from using the feature vs the cost to support it and
> from the sounds of it we don't have numbers on the benefits from using
> it at present.

...although I do have to say looking at the implementation that the cost
seems low, it's just a flag set on an existing transfer.  The only issue
is if we'd get more win from coalesing the entire transaction (or entire
transmit) into a single transfer that could be DMAed and/or requires
fewer trips through the stack which does make it seem like an unclear
tradeoff from the point of view of client drivers

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)

Powered by blists - more mailing lists