linux-kernel - Re: [PATCH v3 5/6] ARM: davinci: Add support for PRUSS on DA850

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]

Message-ID: <20121004163546.GK11149@beef>
Date:	Thu, 4 Oct 2012 12:35:46 -0400
From:	Matt Porter <mporter@...com>
To:	Sekhar Nori <nsekhar@...com>
Cc:	Linux DaVinci Kernel List 
	<davinci-linux-open-source@...ux.davincidsp.com>,
	Russell King <linux@....linux.org.uk>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"Hans J. Koch" <hjk@...sjkoch.de>,
	Linux ARM Kernel List <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v3 5/6] ARM: davinci: Add support for PRUSS on DA850

On Thu, Oct 04, 2012 at 05:52:45PM +0530, Sekhar Nori wrote:
> On 10/3/2012 8:25 PM, Matt Porter wrote:
> > +static struct clk pruss_clk = {
> > +	.name		= "pruss",
> > +	.parent		= &pll0_sysclk2,
> > +	.lpsc		= DA8XX_LPSC0_PRUSS,
> > +};
> > +
> >  static struct clk uart0_clk = {
> >  	.name		= "uart0",
> >  	.parent		= &pll0_sysclk2,
> > @@ -378,6 +384,7 @@ static struct clk_lookup da850_clks[] = {
> >  	CLK(NULL,		"tptc1",	&tptc1_clk),
> >  	CLK(NULL,		"tpcc1",	&tpcc1_clk),
> >  	CLK(NULL,		"tptc2",	&tptc2_clk),
> > +	CLK(NULL,		"pruss",	&pruss_clk),
> 
> This is actually incorrect since we should use device name rather than
> con_id for matching the clock. If there is just one clock that the
> driver needs, connection id should be NULL. Looking at the driver now,
> the clk_get() call seems to pass a valid device pointer. So, I wonder
> how you are able to look up the clock even with a NULL device name.

I doublechecked the clk_get() find implentation to confirm that I indeed
did get lucky here. Since pruss has only one instance and the clk_find()
implementation looks for the best found match, it's able to find the
clock just by the con_id, though it's not the "best possible" match in
the find implementation...it's the "best found" match.. As you noted,
this is incorrect though for a clock expected to be used from a driver
context so I will address this in the update.

-Matt
--
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/