linux-kernel - Re: [PATCH v6 4/4] i2c: npcm: Enable slave in eob interrupt

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: <ZwkFwABviY8ClyUo@smile.fi.intel.com>
Date: Fri, 11 Oct 2024 14:02:24 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Tyrone Ting <warp5tw@...il.com>
Cc: avifishman70@...il.com, tmaimon77@...il.com, tali.perry1@...il.com,
	venture@...gle.com, yuenn@...gle.com, benjaminfair@...gle.com,
	andi.shyti@...nel.org, wsa@...nel.org, rand.sec96@...il.com,
	wsa+renesas@...g-engineering.com, tali.perry@...oton.com,
	Avi.Fishman@...oton.com, tomer.maimon@...oton.com,
	KWLIU@...oton.com, JJLIU0@...oton.com, kfting@...oton.com,
	openbmc@...ts.ozlabs.org, linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Charles Boyer <Charles.Boyer@...-usa.com>,
	Vivekanand Veeracholan <vveerach@...gle.com>
Subject: Re: [PATCH v6 4/4] i2c: npcm: Enable slave in eob interrupt

On Fri, Oct 11, 2024 at 01:52:31PM +0800, Tyrone Ting wrote:
> From: Charles Boyer <Charles.Boyer@...-usa.com>
> 
> Nuvoton slave enable was in user space API call master_xfer, so it is
> subject to delays from the OS scheduler. If the BMC is not enabled for
> slave mode in time for master to send response, then it will NAK the
> address match. Then the PLDM request timeout occurs.
> 
> If the slave enable is moved to the EOB interrupt service routine, then
> the BMC can be ready in slave mode by the time it needs to receive a
> response.

...

> +#if IS_ENABLED(CONFIG_I2C_SLAVE)
> +		/* reenable slave if it was enabled */
> +		if (bus->slave)
> +			iowrite8((bus->slave->addr & 0x7F) | NPCM_I2CADDR_SAEN,

GENMASK()?
But why do we need it? Do we expect this to be 10-bit address or...?

> +				 bus->reg + NPCM_I2CADDR1);
> +#endif

-- 
With Best Regards,
Andy Shevchenko