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From: mkl@pengutronix.de (Marc Kleine-Budde)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v12 10/13] usb: chipidea: add wait vbus lower than OTGSC_BSV before role starts
Date: Thu, 11 Jul 2013 11:31:46 +0200	[thread overview]
Message-ID: <51DE7B82.4030402@pengutronix.de> (raw)
In-Reply-To: <20130711092535.GA11728@nchen-desktop>

On 07/11/2013 11:25 AM, Peter Chen wrote:
> On Thu, Jul 11, 2013 at 09:24:56AM +0200, Marc Kleine-Budde wrote:
>> On 07/11/2013 08:27 AM, Peter Chen wrote:
>>> When the gadget role starts, we need to make sure the vbus is lower
>>> than OTGSC_BSV, or there will be an vbus interrupt since we use
>>> B_SESSION_VALID as vbus interrupt to indicate connect and disconnect.
>>> When the host role starts, it may not be useful to wait vbus to lower
>>> than OTGSC_BSV, but it can indicate some hardware problems like the
>>> vbus is still higher than OTGSC_BSV after we disconnect to host some
>>> time later (500 jiffies currently), which is obvious not correct.
>>
>> Jiffies ist not constant. I think you have to specify the timeout in
>> fractions of HZ. The system ticks with HZ jiffies per second. So a
>> timeout of 500ms is "HZ / 2".
> 
> Thanks, I will use msecs_to_jiffies.

even better.

> 
>>> +/**
>>> + * hw_wait_reg: wait the register value
>>> + *
>>> + * Sometimes, it needs to wait register value before going on.
>>> + * Eg, when switch to device mode, the vbus value should be lower
>>> + * than OTGSC_BSV before connects to host.
>>> + *
>>> + * @ci: the controller
>>> + * @reg: register index
>>> + * @mask: mast bit
>>> + * @value: the bit value to wait
>>> + * @timeout: timeout to indicate an error
>>                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>
>> Better: timeout in jiffies
>>
> 
> As I will use msecs_to_jiffies, @timeout: timeout in millisecond.

Good idea - you might want to use timeout_ms.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |

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  reply	other threads:[~2013-07-11  9:31 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-11  6:27 [PATCH v12 00/13] Add tested id switch and vbus connect detect support for Chipidea Peter Chen
2013-07-11  6:27 ` [PATCH v12 01/13] usb: chipidea: add vbus regulator control Peter Chen
2013-07-11  6:27 ` [PATCH v12 02/13] usb: chipidea: imx: remove vbus regulator operation Peter Chen
2013-07-11  6:37   ` Sascha Hauer
2013-07-11  6:55     ` Peter Chen
2013-07-11  6:27 ` [PATCH v12 03/13] usb: chipidea: udc: otg_set_peripheral is useless for some chipidea users Peter Chen
2013-07-11  6:27 ` [PATCH v12 04/13] usb: chipidea: otg: Add otg file used to access otgsc Peter Chen
2013-07-11  6:27 ` [PATCH v12 05/13] usb: chipidea: Add role init and destory APIs Peter Chen
2013-07-11  6:27 ` [PATCH v12 06/13] usb: chipidea: add otg_cap attribute for otg capable Peter Chen
2013-07-11 15:36   ` Marek Vasut
2013-07-12  2:58     ` Peter Chen
2013-07-12  3:54       ` Marek Vasut
2013-07-12  8:12   ` Alexander Shishkin
2013-07-12  8:25     ` Peter Chen
2013-07-12  9:42       ` Alexander Shishkin
2013-07-12 10:16         ` Peter Chen
2013-07-16  9:45         ` Peter Chen
2013-07-11  6:27 ` [PATCH v12 07/13] usb: chipidea: disable all interrupts and clear all interrupts status Peter Chen
2013-07-11  6:27 ` [PATCH v12 08/13] usb: chipidea: move otg relate things to otg file Peter Chen
2013-07-11  6:27 ` [PATCH v12 09/13] usb: chipidea: add vbus interrupt handler Peter Chen
2013-07-11  6:27 ` [PATCH v12 10/13] usb: chipidea: add wait vbus lower than OTGSC_BSV before role starts Peter Chen
2013-07-11  7:24   ` Marc Kleine-Budde
2013-07-11  9:25     ` Peter Chen
2013-07-11  9:31       ` Marc Kleine-Budde [this message]
2013-07-11  6:27 ` [PATCH v12 11/13] usb: chipidea: udc: misuse flag CI_HDRC_REGS_SHARED and CI_HDRC_PULLUP_ON_VBUS Peter Chen
2013-07-11  6:27 ` [PATCH v12 12/13] usb: chipidea: udc: .pullup is valid when vbus is on at CI_HDRC_PULLUP_ON_VBUS Peter Chen
2013-07-11  6:27 ` [PATCH v12 13/13] usb: chipidea: udc: fix the oops when plugs in usb cable after rmmod gadget Peter Chen
2013-07-11 17:57 ` [PATCH v12 00/13] Add tested id switch and vbus connect detect support for Chipidea Marek Vasut
2013-07-12  3:12   ` Peter Chen
2013-07-12  4:04     ` Marek Vasut
2013-07-12  8:26       ` Peter Chen
2013-07-12 13:18         ` Marek Vasut
2013-07-13  0:36           ` Chen Peter-B29397
2013-07-16  9:43           ` Peter Chen
2013-07-22  1:15             ` Marek Vasut
2013-07-22  1:21               ` Peter Chen
2013-07-22  1:40                 ` Marek Vasut
2013-07-22  1:53                   ` Peter Chen
2013-07-25  5:55                     ` Marek Vasut
2013-07-25  5:58                       ` Peter Chen
2013-07-25 12:36                         ` Marek Vasut
2013-07-19 14:11 ` Fabio Estevam
2013-07-25  6:05 ` Marek Vasut

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