From: Esben Haabendal <esben@haabendal.dk>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Lee Jones <lee.jones@linaro.org>,
"open list\:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
Enrico Weigelt <lkml@metux.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
Darwin Dingel <darwin.dingel@alliedtelesis.co.nz>,
Jisheng Zhang <Jisheng.Zhang@synaptics.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
He Zhe <zhe.he@windriver.com>, Marek Vasut <marex@denx.de>,
Douglas Anderson <dianders@chromium.org>,
Paul Burton <paul.burton@mips.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] serial: 8250: Add support for using platform_device resources
Date: Tue, 14 May 2019 14:02:40 +0200 [thread overview]
Message-ID: <87zhnpkzvj.fsf@haabendal.dk> (raw)
In-Reply-To: <CAHp75VetoajaeqUnUuj4sNjhujqDkbqvQmxE+LMtzFN4so_jwA@mail.gmail.com> (Andy Shevchenko's message of "Tue, 14 May 2019 12:37:25 +0300")
Andy Shevchenko <andy.shevchenko@gmail.com> writes:
> On Tue, May 14, 2019 at 12:23 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
>> On Tue, May 14, 2019 at 10:24 AM Esben Haabendal <esben@haabendal.dk> wrote:
>
>> > Please take a look at https://lkml.org/lkml/2019/4/9/576
>> > ("[PATCH v2 2/4] mfd: ioc3: Add driver for SGI IOC3 chip")
>>
>> Thank you for this link.
>> Now, look at this comment:
>>
>> + /*
>> + * Map all IOC3 registers. These are shared between subdevices
>> + * so the main IOC3 module manages them.
>> + */
>>
>> Is it your case? Can we see the code?
>
> They do not request resources by the way.
Actually, that looks like a bug in ioc3.c driver.
It is using mfd_add_devices() with a mem_base that has not been properly
requested, and the platform_get_resource() calls made by child drivers
does not guarantee exclusive access to the memory resources, as they are
not inserted in the root memory resource tree.
> You may do the same, I told you this several times.
In drivers/mfd/ioc3.c:
First, the uart resources are defined. The register memory resource is
defined relative to the mfd driver memory resource.
+static struct resource ioc3_uarta_resources[] = {
+ DEFINE_RES_MEM(offsetof(struct ioc3, sregs.uarta),
+ sizeof_field(struct ioc3, sregs.uarta)),
+ DEFINE_RES_IRQ(6)
+};
This is then used when creating the uart cell.
+ cell->name = "ioc3-serial8250";
+ cell->id = ioc3_serial_id++;
+ cell->resources = ioc3_uarta_resources;
+ cell->num_resources = ARRAY_SIZE(ioc3_uarta_resources);
Finally, the mfd_add_devices() call is made, giving the resource for the
BAR0 region (&ipd->pdev->resource[0]) as mem_base argument:
+ mfd_add_devices(&ipd->pdev->dev, -1, ioc3_mfd_cells,
+ cell - ioc3_mfd_cells, &ipd->pdev->resource[0],
+ 0, ipd->domain);
This is just what I want to do.
But in order to guarantee exclusive access to the memory resource, I
need to have it requested.
/Esben
next prev parent reply other threads:[~2019-05-14 12:02 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-30 14:04 [PATCH] serial: 8250: Add support for using platform_device resources Esben Haabendal
2019-04-30 15:37 ` Andy Shevchenko
2019-05-01 7:17 ` Esben Haabendal
2019-05-02 10:45 ` Andy Shevchenko
2019-05-02 12:41 ` Esben Haabendal
2019-05-02 15:31 ` Andy Shevchenko
2019-05-06 15:46 ` Esben Haabendal
2019-05-06 16:44 ` Andy Shevchenko
2019-05-06 17:40 ` Esben Haabendal
2019-05-06 21:04 ` Andy Shevchenko
2019-05-07 9:32 ` Lee Jones
2019-05-07 9:36 ` Lee Jones
2019-05-07 11:32 ` Esben Haabendal
2019-05-07 11:35 ` Esben Haabendal
2019-05-07 11:53 ` Andy Shevchenko
2019-05-07 12:22 ` Esben Haabendal
2019-05-07 15:08 ` Andy Shevchenko
2019-05-14 7:22 ` Esben Haabendal
2019-05-14 9:23 ` Andy Shevchenko
2019-05-14 9:37 ` Andy Shevchenko
2019-05-14 12:02 ` Esben Haabendal [this message]
2019-05-14 12:42 ` Andy Shevchenko
2019-05-14 12:02 ` Esben Haabendal
2019-05-14 12:38 ` Andy Shevchenko
2019-05-14 7:37 ` Esben Haabendal
2019-05-02 19:41 ` Enrico Weigelt, metux IT consult
2019-05-06 15:19 ` Esben Haabendal
2019-05-21 11:34 ` [PATCH resend] " Esben Haabendal
2019-05-21 12:42 ` Andy Shevchenko
2019-05-21 14:43 ` Esben Haabendal
2019-05-21 17:03 ` Andy Shevchenko
2019-05-21 13:11 ` Greg Kroah-Hartman
2019-05-21 14:45 ` Esben Haabendal
2019-05-21 14:53 ` Greg Kroah-Hartman
2019-06-11 18:11 ` Enrico Weigelt, metux IT consult
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