linux-kernel - Re: [PATCH V3] Add support for flag status register on Micron chips.

lists.openwall.net		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 linux-cve-announce 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:	Sat, 26 Apr 2014 11:10:13 +0800
From:	Huang Shijie <shijie8@...il.com>
To:	Marek Vasut <marex@...x.de>
Cc:	Huang Shijie <b32955@...escale.com>,
	Graham Moore <grmoore@...era.com>, ggrahammoore@...il.com,
	Geert Uytterhoeven <geert+renesas@...ux-m68k.org>,
	Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Jingoo Han <jg1.han@...sung.com>, linux-kernel@...r.kernel.org,
	Yves Vandervennet <rocket.yvanderv@...il.com>,
	linux-mtd@...ts.infradead.org,
	Insop Song <insop.song@...nspeed.com>,
	Alan Tull <atull@...era.com>,
	Sourav Poddar <sourav.poddar@...com>,
	Brian Norris <computersforpeace@...il.com>,
	David Woodhouse <dwmw2@...radead.org>,
	Dinh Nguyen <dinguyen@...era.com>
Subject: Re: [PATCH V3] Add support for flag status register on Micron chips.

On Sat, Apr 26, 2014 at 12:12:24AM +0200, Marek Vasut wrote:
> > > > the drivers may fills this hook itself, so the code should like this:
> > > >    --------------------------------------------------
> > > > 	
> > > > 	if ((info->flags & USE_FSR) &&
> > > > 	
> > > > 	       	nor->wait_till_ready == spi_nor_wait_till_fsr_ready)
> > > > 		
> > > > 		nor->wait_till_ready = spi_nor_wait_till_fsr_ready;
> > > > 		
> > > >    --------------------------------------------------
> > > 
> > > I sense a misdesign of the SPI NOR subsystem here. The subsystem and the
> > > driver compete for a function pointer here ? I guess one should have
> > > precedence in some way then ... and also, they should be two different
> > > pointers, where the subsystem decides which to use.
> > 
> > the subsystem do not decides which one to use, the driver decides which one
> > to use.
> > 
> > If driver has its own @wait_till_ready , it means the driver knows the
> > feature, and has implemented it in its own @wait_till_ready.
> > 
> > If the driver does not fill any wait_till_ready, it means the driver will
> > use the default @wait_till_ready. We can treat the
> > spi_nor_wait_till_fsr_ready as a default hook too.
> 
> I see the driver overwriting a hook previously set by the subsystem. This 
not sure ;)

The driver set the hooks before the subsystem set these hooks.

If the driver has already set the @wait_till_ready hook before it calls
the spi_nor_scan, the subsystem will not set the hook anymore.

Please see the spi_nor_check().

thanks
Huang Shijie


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/