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From: Ralph Metzler <rjkm@metzlerbros.de>
To: "Jasmin J." <jasmin@anw.at>
Cc: linux-media@vger.kernel.org, mchehab@s-opensource.com,
	rjkm@metzlerbros.de, d.scheller@gmx.net
Subject: Re: [PATCH V2 0/3] Add timers to en50221 protocol driver
Date: Sun, 18 Feb 2018 21:55:50 +0100	[thread overview]
Message-ID: <23177.59478.243278.702389@morden.metzler> (raw)
In-Reply-To: <ef72a382-5d30-526c-ae09-ed50d9d4790d@anw.at>

Hi Jasmin,

Jasmin J. writes:
 > Hi!
 > 
 > Please hold on in merging this series, because I have to investigate a hint
 > I got related to the buffer size handshake of the protocol driver:
 >   https://www.linuxtv.org/pipermail/linux-dvb/2007-July/019116.html
 > 
 > BR,
 >    Jasmin


So, there seem to be two bugs:

1. The SW bit is cleared too early during the whole buffer size negotiation.

This should be fixed.


2. IRQEN = CMDREG_DAIE = 0x80 is always set in the command register.

DAIE and FRIE were introduced as recommendation in Cenelec R06-001:1998 and are a requirement for
CI+.

They could cause problems if the IRQ line goes high and the interrupt is enabled but not handled.
They should not cause a problem if the host ignores the interrupt or if the CAM does not support it,
but one never knows with some CAMs ...

So, they should probably only be used if both the host and module say they support it.
R06 does not mention it but CI+ also requires a CIS entry to be present in modules 
supporting this feature.



Regards,
Ralph

  reply	other threads:[~2018-02-18 20:55 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-21 13:22 [PATCH V2 0/3] Add timers to en50221 protocol driver Jasmin J.
2017-12-21 13:22 ` [PATCH V2 1/3] media: dvb-core: Store device structure in dvb_register_device Jasmin J.
2018-02-13 23:29   ` Jasmin J.
2017-12-21 13:22 ` [PATCH V2 2/3] media: dvb-core: Added timers for dvb_ca_en50221_write_data Jasmin J.
2018-02-13 23:29   ` Jasmin J.
2018-03-05 20:03     ` Mauro Carvalho Chehab
2017-12-21 13:22 ` [PATCH V2 3/3] media: dvb-core: Added documentation for ca sysfs timer nodes Jasmin J.
2018-02-13 23:29   ` Jasmin J.
2018-02-13 23:29 ` [PATCH V2 0/3] Add timers to en50221 protocol driver Jasmin J.
2018-02-18 20:55   ` Ralph Metzler [this message]
2018-02-18 21:18     ` Jasmin J.
2018-02-19  0:24       ` Ralph Metzler

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