netdev - Re: [PATCH 2/2] DM9000B: Fix PHY power for network down/up

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4D62D323.7010403@henry.nestler.mail.gmail.com>
Date:	Mon, 21 Feb 2011 22:03:31 +0100
From:	Henry Nestler <henry.nestler@...il.com>
To:	Sergei Shtylyov <sshtylyov@...sta.com>
CC:	netdev@...r.kernel.org, tori@...appy.mine.nu,
	akpm@...ux-foundation.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 2/2] DM9000B: Fix PHY power for network down/up

On 21.02.2011 12:14, Sergei Shtylyov wrote:
> On 21-02-2011 0:45, Henry Nestler wrote:
> 
>> DM9000 revision B needs 1 ms delay after PHY power on (see spec), and PHY
>> power must on in register
> 
>     Couldn't parse that.

This can read in manual DM900B-12-DS-F02 from September 2 2010, Page 14:
"If this Register 1FH bit 0 is updated from '1' to '0', the all
Registers can not be accessed within 1ms."

The example driver code waits 2 ms.

>> diff --git a/drivers/net/dm9000.c b/drivers/net/dm9000.c
>> index 2d4c4fc..5925569 100644
>> --- a/drivers/net/dm9000.c
>> +++ b/drivers/net/dm9000.c
> [...]
>> @@ -1194,6 +1191,10 @@ dm9000_open(struct net_device *dev)
>>   	if (request_irq(dev->irq, dm9000_interrupt, irqflags, dev->name, dev))
>>   		return -EAGAIN;
>>
>> +	/* GPIO0 on pre-activate PHY, Reg 1F is not set by reset */
>> +	iow(db, DM9000_GPR, 0);	/* REG_1F bit0 activate phyxcer */
>> +	udelay(1000); /* delay needs by DM9000B */
> 
>     Why not mdelay(1)?

Because udelay is the base of mdelay.
See include/linux/delay.h:31

#define mdelay(n) ... udelay((n)*1000)

-- 
Henry N.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html