From: Alan Tull <delicious.quinoa@gmail.com>
To: "Li, Yi" <yi1.li@linux.intel.com>
Cc: Moritz Fischer <moritz.fischer@ettus.com>,
Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
linux-fpga@vger.kernel.org
Subject: Re: [RFC 4/8] doc: fpga-mgr: separate getting/locking FPGA manager
Date: Fri, 17 Feb 2017 15:55:37 -0600 [thread overview]
Message-ID: <CANk1AXT-k4GAUKKC_vBMw4Lg9_LLQs+CGmQkkS7LTnkGc5TUAg@mail.gmail.com> (raw)
In-Reply-To: <20c28527-8a58-7aa0-489c-5bef7228a159@linux.intel.com>
On Fri, Feb 17, 2017 at 11:14 AM, Li, Yi <yi1.li@linux.intel.com> wrote:
> hi Alan
>
>
> On 2/15/2017 10:14 AM, Alan Tull wrote:
>>
>> Document that getting a reference to a FPGA Manager has been
>> separated from locking the FPGA Mangager for use.
>>
>> fpga_mgr_lock/unlock functions get/release mutex.
>>
>> of_fpga_mgr_get, fpga_mgr_get, and fpga_mgr_put no longer lock
>> the FPGA manager mutex.
>>
>> This makes it more straigtforward to save a reference to
>> a FPGA manager and only attempting to lock it when programming
>> the FPGA.
>
>
> New to the FPGA world, but I like the idea of shorter lock. Separating the
> lock from fpga_mgr_get will give underline FPGA device drivers more
> flexibility to acquire the mgr pointer.
> One newbie question, since the underline FPGA device driver does the
> fpga_mgr_register during probe, each manager instance belongs to that FPGA
> device only. What's the use to keep tracking the usage reference with
> fpga_mgr_put/get function, or is it enough to increase/decrease dev
> reference count in fpga_mgr_register/unregister function?
Hi Yi,
That's a good though but the code that creates the fpga mgr device might not be
the code that needs to hold a reference to it. The device tree
implementation is an
example of this. The fpga mgr devices are created completely
separately from the
fpga regions.
Alan
>
> Thanks,
> Yi
>
>>
>> Signed-off-by: Alan Tull <atull@kernel.org>
>> ---
>> Documentation/fpga/fpga-mgr.txt | 19 ++++++++++++++++++-
>> 1 file changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/fpga/fpga-mgr.txt
>> b/Documentation/fpga/fpga-mgr.txt
>> index 78f197f..06d5d5b 100644
>> --- a/Documentation/fpga/fpga-mgr.txt
>> +++ b/Documentation/fpga/fpga-mgr.txt
>> @@ -53,13 +53,26 @@ To get/put a reference to a FPGA manager:
>> struct fpga_manager *of_fpga_mgr_get(struct device_node *node);
>> struct fpga_manager *fpga_mgr_get(struct device *dev);
>> -Given a DT node or device, get an exclusive reference to a FPGA
>> manager.
>> +Given a DT node or device, get an reference to a FPGA manager. Pointer
>> +can be saved until you are ready to program the FPGA.
>> void fpga_mgr_put(struct fpga_manager *mgr);
>> Release the reference.
>> +To get exclusive control of a FPGA manager:
>> +-------------------------------------------
>> +
>> + int fpga_mgr_lock(struct fpga_magager *mgr);
>> +
>> +Call fpga_mgr_lock and verify that it returns 0 before attempting to
>> +program the FPGA.
>> +
>> + void fpga_mgr_unlock(struct fpga_magager *mgr);
>> +
>> +Call fpga_mgr_unlock when done programming the FPGA.
>> +
>> To register or unregister the low level FPGA-specific driver:
>> -------------------------------------------------------------
>> @@ -95,11 +108,13 @@ int ret;
>> /* Get exclusive control of FPGA manager */
>> struct fpga_manager *mgr = of_fpga_mgr_get(mgr_node);
>> +ret = fpga_mgr_lock(mgr);
>> /* Load the buffer to the FPGA */
>> ret = fpga_mgr_buf_load(mgr, &info, buf, count);
>> /* Release the FPGA manager */
>> +fpga_mgr_unlock(mgr);
>> fpga_mgr_put(mgr);
>> @@ -124,11 +139,13 @@ int ret;
>> /* Get exclusive control of FPGA manager */
>> struct fpga_manager *mgr = of_fpga_mgr_get(mgr_node);
>> +ret = fpga_mgr_lock(mgr);
>> /* Get the firmware image (path) and load it to the FPGA */
>> ret = fpga_mgr_firmware_load(mgr, &info, path);
>> /* Release the FPGA manager */
>> +fpga_mgr_unlock(mgr);
>> fpga_mgr_put(mgr);
>>
>
>
next prev parent reply other threads:[~2017-02-17 21:56 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-15 16:14 FPGA Region enhancements and fixes Alan Tull
2017-02-15 16:14 ` [RFC 1/8] fpga-mgr: add a single function for fpga loading methods Alan Tull
2017-02-16 0:36 ` matthew.gerlach
2017-02-15 16:14 ` [RFC 2/8] fpga-region: support more than one overlay per FPGA region Alan Tull
2017-02-16 16:50 ` matthew.gerlach
2017-02-16 17:35 ` Alan Tull
2017-02-15 16:14 ` [RFC 3/8] fpga-bridge: add non-dt support Alan Tull
2017-02-15 16:14 ` [RFC 4/8] doc: fpga-mgr: separate getting/locking FPGA manager Alan Tull
2017-02-17 17:14 ` Li, Yi
2017-02-17 21:55 ` Alan Tull [this message]
2017-02-17 17:52 ` Moritz Fischer
2017-02-17 22:02 ` Alan Tull
2017-02-15 16:14 ` [RFC 5/8] " Alan Tull
2017-02-15 16:14 ` [RFC 6/8] fpga-region: separate out common code to allow non-dt support Alan Tull
2017-02-15 16:14 ` [RFC 7/8] fpga-region: add sysfs interface Alan Tull
2017-02-15 17:21 ` Jason Gunthorpe
2017-02-15 17:46 ` Alan Tull
2017-02-15 17:55 ` Moritz Fischer
2017-02-15 18:06 ` Jason Gunthorpe
2017-02-15 18:23 ` Alan Tull
2017-02-15 18:31 ` Moritz Fischer
2017-02-15 19:49 ` Jason Gunthorpe
2017-02-15 22:49 ` Alan Tull
2017-02-15 23:07 ` Jason Gunthorpe
2017-02-15 20:07 ` matthew.gerlach
2017-02-15 20:37 ` Jason Gunthorpe
2017-02-15 20:54 ` Moritz Fischer
2017-02-15 21:15 ` Jason Gunthorpe
2017-02-15 21:36 ` Moritz Fischer
2017-02-15 22:42 ` Alan Tull
2017-02-16 0:16 ` Moritz Fischer
2017-02-16 17:47 ` Alan Tull
2017-02-16 17:56 ` Jason Gunthorpe
2017-02-16 18:11 ` Moritz Fischer
2017-02-17 22:28 ` Yves Vandervennet
2017-02-18 2:30 ` Moritz Fischer
2017-02-18 12:45 ` Nadathur, Sundar
2017-02-18 20:10 ` Alan Tull
2017-02-18 20:45 ` Moritz Fischer
2017-02-19 15:00 ` Alan Tull
2017-02-19 23:16 ` Alan Tull
2017-02-20 23:49 ` Moritz Fischer
2017-02-21 18:33 ` Alan Tull
2017-02-22 3:13 ` Nadathur, Sundar
2017-02-22 3:49 ` Moritz Fischer
2017-02-22 5:12 ` Jason Gunthorpe
2017-02-22 5:38 ` Moritz Fischer
2017-02-22 5:46 ` Nadathur, Sundar
2017-02-22 6:05 ` Moritz Fischer
2017-02-22 16:44 ` Jason Gunthorpe
2017-02-22 17:50 ` Moritz Fischer
2017-02-22 17:54 ` Jason Gunthorpe
2017-02-22 17:57 ` Moritz Fischer
2017-02-22 16:33 ` Alan Tull
2017-02-22 16:44 ` Moritz Fischer
2017-02-22 16:52 ` Alan Tull
2017-02-27 20:09 ` Alan Tull
2017-02-27 22:49 ` Moritz Fischer
2017-02-28 0:04 ` matthew.gerlach
2017-02-15 21:20 ` Anatolij Gustschin
2017-02-15 16:14 ` [RFC 8/8] doc: fpga: add sysfs document for fpga region Alan Tull
2017-02-28 17:35 ` FPGA Region enhancements and fixes Alan Tull
2017-02-28 22:03 ` Alan Tull
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