From: Kevin Hilman <khilman@ti.com>
To: "Govindraj.R" <govindraj.raja@ti.com>
Cc: linux-omap@vger.kernel.org, linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Tony Lindgren <tony@atomide.com>, Partha Basak <p-basak2@ti.com>,
Vishwanath Sripathy <vishwanath.bs@ti.com>,
Rajendra Nayak <rnayak@ti.com>,
Santosh Shilimkar <santosh.shilimkar@ti.com>
Subject: Re: [PATCH v6 14/16] OMAP2+: UART: Take console_lock in suspend path if not taken
Date: Tue, 11 Oct 2011 12:01:17 -0700 [thread overview]
Message-ID: <87sjmz1hfm.fsf@ti.com> (raw)
In-Reply-To: <1317380561-661-5-git-send-email-govindraj.raja@ti.com> (Govindraj R.'s message of "Fri, 30 Sep 2011 16:32:39 +0530")
"Govindraj.R" <govindraj.raja@ti.com> writes:
> In suspend path the console_lock is taken by uart_port_suspend
> however when no_console_suspend is used console_lock is not taken.
>
> During system wide suspend omap_pwr_domain hooks cut all
> clocks that are left enabled. So its unsafe to proceed printing after
> clocks are cut by pwr_domain hooks.
As I've mentioned in previous reviews, when no_console_suspend is
enabled, the user has explicitly requested console output during
suspend. In order to support that, we should not be cutting clocks at
all in that mode.
One way to address this would be to just disable runtime PM in the
->prepare method of the driver if no_console_suspend is enabled.
> Also pm_runtime will be disabled after dpm_suspend devices happens.
Not sure why this is relevant.
> So buffer all prints in suspend path by taking console_lock and print
> them back safely after power domain hooks re-enable clocks back.
>
> Use CONFIG_SERIAL_OMAP_CONSOLE macro check to take console_lock since
> console ops are available only if omap console is defined.
> omap-serial can be built as module without console support.
Please revisit use of #ifdefs. (c.f. #ifdefs are ugly in
Documentation/SubmittingPatches)
Kevin
WARNING: multiple messages have this Message-ID (diff)
From: khilman@ti.com (Kevin Hilman)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v6 14/16] OMAP2+: UART: Take console_lock in suspend path if not taken
Date: Tue, 11 Oct 2011 12:01:17 -0700 [thread overview]
Message-ID: <87sjmz1hfm.fsf@ti.com> (raw)
In-Reply-To: <1317380561-661-5-git-send-email-govindraj.raja@ti.com> (Govindraj R.'s message of "Fri, 30 Sep 2011 16:32:39 +0530")
"Govindraj.R" <govindraj.raja@ti.com> writes:
> In suspend path the console_lock is taken by uart_port_suspend
> however when no_console_suspend is used console_lock is not taken.
>
> During system wide suspend omap_pwr_domain hooks cut all
> clocks that are left enabled. So its unsafe to proceed printing after
> clocks are cut by pwr_domain hooks.
As I've mentioned in previous reviews, when no_console_suspend is
enabled, the user has explicitly requested console output during
suspend. In order to support that, we should not be cutting clocks at
all in that mode.
One way to address this would be to just disable runtime PM in the
->prepare method of the driver if no_console_suspend is enabled.
> Also pm_runtime will be disabled after dpm_suspend devices happens.
Not sure why this is relevant.
> So buffer all prints in suspend path by taking console_lock and print
> them back safely after power domain hooks re-enable clocks back.
>
> Use CONFIG_SERIAL_OMAP_CONSOLE macro check to take console_lock since
> console ops are available only if omap console is defined.
> omap-serial can be built as module without console support.
Please revisit use of #ifdefs. (c.f. #ifdefs are ugly in
Documentation/SubmittingPatches)
Kevin
next prev parent reply other threads:[~2011-10-11 19:01 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-30 11:02 [PATCH v6 10/16] OMAP2+: UART: Modify omap_uart_can_sleep function Govindraj.R
2011-09-30 11:02 ` Govindraj.R
2011-09-30 11:02 ` [PATCH v6 11/16] OMAP2+: UART: Move errata handling from serial.c to omap-serial Govindraj.R
2011-09-30 11:02 ` Govindraj.R
2011-10-11 21:01 ` Kevin Hilman
2011-10-11 21:01 ` Kevin Hilman
2011-10-12 10:43 ` Govindraj
2011-10-12 10:43 ` Govindraj
2011-09-30 11:02 ` [PATCH v6 12/16] OMAP2+: UART: Allow UART parameters to be configured from board file Govindraj.R
2011-09-30 11:02 ` Govindraj.R
2011-10-11 18:53 ` Kevin Hilman
2011-10-11 18:53 ` Kevin Hilman
2011-10-12 10:44 ` Govindraj
2011-10-12 10:44 ` Govindraj
2011-09-30 11:02 ` [PATCH v6 13/16] OMAP2+: UART: Make the RX_TIMEOUT for DMA configurable for each UART Govindraj.R
2011-09-30 11:02 ` Govindraj.R
2011-09-30 11:02 ` [PATCH v6 14/16] OMAP2+: UART: Take console_lock in suspend path if not taken Govindraj.R
2011-09-30 11:02 ` Govindraj.R
2011-10-11 19:01 ` Kevin Hilman [this message]
2011-10-11 19:01 ` Kevin Hilman
2011-10-12 11:23 ` Govindraj
2011-10-12 11:23 ` Govindraj
2011-10-12 23:47 ` Kevin Hilman
2011-10-12 23:47 ` Kevin Hilman
2011-10-13 1:11 ` Govindraj
2011-10-13 1:11 ` Govindraj
2011-09-30 11:02 ` [PATCH v6 15/16] OMAP2+: UART: Enable back uart clocks with runtime API for early console Govindraj.R
2011-09-30 11:02 ` Govindraj.R
2011-10-11 21:06 ` Kevin Hilman
2011-10-11 21:06 ` Kevin Hilman
2011-10-12 14:04 ` Govindraj
2011-10-12 14:04 ` Govindraj
2011-10-13 0:00 ` Kevin Hilman
2011-10-13 0:00 ` Kevin Hilman
2011-10-13 1:22 ` Govindraj
2011-10-13 1:22 ` Govindraj
2011-10-13 21:01 ` Kevin Hilman
2011-10-13 21:01 ` Kevin Hilman
2011-10-14 14:18 ` Govindraj
2011-10-14 14:18 ` Govindraj
2011-10-14 17:12 ` Kevin Hilman
2011-10-14 17:12 ` Kevin Hilman
2011-09-30 11:02 ` [PATCH v6 16/16] OMAP2+: UART: Do not gate uart clocks if used for debug_prints Govindraj.R
2011-09-30 11:02 ` Govindraj.R
2011-10-11 18:24 ` [PATCH v6 10/16] OMAP2+: UART: Modify omap_uart_can_sleep function Kevin Hilman
2011-10-11 18:24 ` Kevin Hilman
2011-10-12 13:38 ` Govindraj
2011-10-12 13:38 ` Govindraj
2011-10-12 19:41 ` Kevin Hilman
2011-10-12 19:41 ` Kevin Hilman
2011-10-13 1:09 ` Govindraj
2011-10-13 1:09 ` Govindraj
2011-10-13 6:59 ` Jean Pihet
2011-10-13 6:59 ` Jean Pihet
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