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From: Tony Lindgren <tony@atomide.com>
To: Suman Anna <s-anna@ti.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	richardcochran@gmail.com, Russell King <linux@arm.linux.org.uk>,
	linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, nsekhar@ti.com
Subject: Re: [PATCH v3 3/3] pci: dra7xx: use pdata callbacks to perform reset
Date: Wed, 27 Jan 2016 10:56:49 -0800	[thread overview]
Message-ID: <20160127185649.GV19432@atomide.com> (raw)
In-Reply-To: <56A90971.4020409@ti.com>

* Suman Anna <s-anna@ti.com> [160127 10:17]:
> On 01/27/2016 11:31 AM, Tony Lindgren wrote:
> > Why do you need another reset here? Can't you just implement PM runtime
> > in the driver and do the usual pm_runtime_put_sync followed by
> > pm_runtime_disable?
> 
> The omap_hwmod_enable/disable code does not deal with hardresets (PRCM
> reset lines) and so the pm_runtime_get_sync/put_sync only end up dealing
> with clocks, and we need to invoke the reset functions separately.
> Modules with softresets in SYSCONFIG are ok, as they are dealt with
> properly.

Hmm _reset() in omap_hwmod.c has this to call _assert_hardreset:

	if (oh->class->reset) {
		r = oh->class->reset(oh);
	} else {
		if (oh->rst_lines_cnt > 0) {
			for (i = 0; i < oh->rst_lines_cnt; i++)
				_assert_hardreset(oh, oh->rst_lines[i].name);
			return 0;
		} else {
			r = _ocp_softreset(oh);
			if (r == -ENOENT)
				r = 0;
		}
	}

Care to explain what exactly the problem with the hwmod code not doing
the reset on init?

And why do you need to do another reset in dra7xx_pcie_remove()?

> > Basically I'm wondering how come we need these platform data callbacks
> > at all.
> 
> The hardresets are controlled through the
> omap_device_assert(deassert)_hardreset functions, and since these are
> limited to mach-omap2, we are invoking them through platform data callbacks.

Right.. But I'm wondering about the why you need to do this in the
driver at all part :)

Regards,

Tony

  reply	other threads:[~2016-01-27 18:56 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-14 14:11 [PATCH v3 0/3] dra7xx: get pcie working in mainline Kishon Vijay Abraham I
2016-01-14 14:11 ` [PATCH v3 1/3] ARM: DRA7: hwmod: Add reset data for PCIe Kishon Vijay Abraham I
2016-02-08  1:50   ` Paul Walmsley
2016-01-14 14:11 ` [PATCH v3 2/3] ARM: DRA7: add pdata-quirks to do reset of PCIe Kishon Vijay Abraham I
2016-01-15 19:19   ` Suman Anna
2016-01-15 19:22     ` Tony Lindgren
2016-01-15 19:41       ` Suman Anna
2016-01-18  9:12         ` Sekhar Nori
2016-01-27 17:23           ` Tony Lindgren
2016-01-14 14:11 ` [PATCH v3 3/3] pci: dra7xx: use pdata callbacks to perform reset Kishon Vijay Abraham I
2016-01-27 17:31   ` Tony Lindgren
2016-01-27 18:16     ` Suman Anna
2016-01-27 18:56       ` Tony Lindgren [this message]
2016-01-27 23:16         ` Suman Anna
2016-01-28 18:31           ` Tony Lindgren
2016-01-28 21:15             ` Suman Anna
2016-02-02 10:40             ` Kishon Vijay Abraham I
2016-02-05  4:19               ` Kishon Vijay Abraham I
2016-02-08  2:48               ` Paul Walmsley
2016-02-08 20:56                 ` Suman Anna
2016-02-09  8:49                   ` Paul Walmsley
2016-02-09 17:40                     ` Suman Anna
2016-02-09 19:36                       ` Paul Walmsley
2016-02-10  1:42                         ` Suman Anna
2016-02-10  5:38                           ` Kishon Vijay Abraham I
2016-02-11 19:27                             ` Paul Walmsley
2016-02-11 22:04                               ` Suman Anna
2016-02-12  6:49                               ` Kishon Vijay Abraham I
2016-02-12 17:20                                 ` Suman Anna
2016-02-18 14:21                                   ` Sekhar Nori
2016-02-18 17:23                                     ` Paul Walmsley
2016-02-18 18:27                                       ` Suman Anna
2016-02-22  6:18                                     ` Kishon Vijay Abraham I
2016-02-22  6:31                                       ` Paul Walmsley
2016-02-22  9:55                                         ` Kishon Vijay Abraham I
2016-02-23 11:57                                           ` Kishon Vijay Abraham I
2016-02-23 18:28                                             ` Paul Walmsley
2016-02-24  6:21                                               ` Kishon Vijay Abraham I
2016-03-01  8:25                                                 ` Paul Walmsley
2016-03-01 11:55                                                   ` Kishon Vijay Abraham I
2016-03-01 14:43                                                     ` Bjorn Helgaas
2016-03-01 16:55                                                     ` Suman Anna
2016-02-11 20:43                             ` Suman Anna
2016-02-12  6:55                               ` Kishon Vijay Abraham I
2016-02-10  5:36                         ` Kishon Vijay Abraham I

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