From: Christopher Bostic <cbostic@linux.vnet.ibm.com>
To: Jeremy Kerr <jk@ozlabs.org>, Joel Stanley <joel@jms.id.au>
Cc: Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Russell King <linux@armlinux.org.uk>,
rostedt@goodmis.org, mingo@redhat.com,
Greg KH <gregkh@linuxfoundation.org>,
devicetree <devicetree@vger.kernel.org>,
linux-arm-kernel@lists.infradead.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrew Jeffery <andrew@aj.id.au>,
Alistair Popple <alistair@popple.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
"Edward A . James" <eajames@us.ibm.com>
Subject: Re: [PATCH v6 19/23] drivers/fsi: Add GPIO based FSI master
Date: Thu, 11 May 2017 11:14:13 -0500 [thread overview]
Message-ID: <f3b94de2-9dee-3c5c-f5d4-579824abb0d0@linux.vnet.ibm.com> (raw)
In-Reply-To: <a079022b-8434-a204-c9b4-696a0580fc8c@ozlabs.org>
On 5/10/17 8:58 PM, Jeremy Kerr wrote:
> Hi Chris,
>
>> I don't think we'd want this per master. The lock is for the 'top'
>> master issuing commands. Only the top master can initiate any
>> transactions on the bus to any devices connected downstream. Downstream
>> masters such as hub masters, etc... cannot initiate a command.
> I think what Joel meant there was that we have it per *GPIO* master; if
> there are two GPIO masters on a system, there's no need to provide
> mutual exclusion to each (separate) set of GPIOs.
>
> To implement this, we'd just move the lock into struct fsi_master_gpio.
Hi Jeremy,
Understand now -will make the change.
Thanks
-Chris
> Cheers,
>
>
> Jeremy
>
next prev parent reply other threads:[~2017-05-11 16:14 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-10 19:46 [PATCH v6 00/23] FSI device driver implementation Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 01/23] drivers/fsi: Add fsi master definition Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 02/23] drivers/fsi: Add slave definition Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 03/23] drivers/fsi: Add empty master scan Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 04/23] drivers/fsi: Add crc4 helpers Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 05/23] drivers/fsi: Add slave & master read/write APIs Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 06/23] drivers/fsi: Set up links for slave communication Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 07/23] drivers/fsi: Implement slave initialisation Christopher Bostic
2017-05-02 6:24 ` Joel Stanley
2017-05-02 18:58 ` Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 08/23] drivers/fsi: Set slave SMODE to init communication Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 09/23] drivers/fsi: scan slaves & register devices Christopher Bostic
2017-05-10 7:30 ` Joel Stanley
2017-05-10 18:24 ` Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 10/23] drivers/fsi: Add device read/write/peek API Christopher Bostic
2017-05-02 5:25 ` [v6,10/23] " Brad Bishop
2017-05-10 8:13 ` [PATCH v6 10/23] " Joel Stanley
2017-05-10 18:38 ` Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 11/23] drivers/fsi: Add master unscan Christopher Bostic
2017-05-10 7:31 ` Joel Stanley
2017-05-10 18:33 ` Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 12/23] drivers/fsi: Add documentation for GPIO bindings Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 13/23] drivers/fsi: Add client driver register utilities Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 14/23] drivers/fsi: Add sysfs files for FSI master & slave accesses Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 15/23] drivers/fsi: expose direct-access slave API Christopher Bostic
2017-04-10 19:46 ` [PATCH v6 16/23] drivers/fsi: Add tracepoints for low-level operations Christopher Bostic
2017-04-10 19:47 ` [PATCH v6 17/23] drivers/fsi: Add error handling for slave communication errors Christopher Bostic
2017-04-10 19:47 ` [PATCH v6 18/23] drivers/fsi: Document FSI master sysfs files in ABI Christopher Bostic
2017-05-10 7:30 ` Joel Stanley
2017-05-10 18:20 ` Christopher Bostic
2017-04-10 19:47 ` [PATCH v6 19/23] drivers/fsi: Add GPIO based FSI master Christopher Bostic
2017-05-10 7:30 ` Joel Stanley
2017-05-10 18:15 ` Christopher Bostic
2017-05-11 1:58 ` Jeremy Kerr
2017-05-11 16:14 ` Christopher Bostic [this message]
2017-04-10 19:47 ` [PATCH v6 20/23] drivers/fsi/gpio: Add tracepoints for GPIO master Christopher Bostic
2017-04-10 19:47 ` [PATCH v6 21/23] drivers/fsi: Add SCOM FSI client device driver Christopher Bostic
2017-04-10 19:47 ` [PATCH v6 22/23] drivers/ fsi: Add hub master support Christopher Bostic
2017-04-10 19:47 ` [PATCH v6 23/23] drivers/fsi: Use asynchronous slave mode Christopher Bostic
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