public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Maciej Szmigiero <mhej@o2.pl>
To: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [V4L][SAA7134] fix tda9887 detection on cold and eeprom read corruption on warm Medion 7134
Date: Tue, 09 Nov 2010 16:02:44 +0100	[thread overview]
Message-ID: <4CD96294.8010905@o2.pl> (raw)
In-Reply-To: <4CD9280C.40204@infradead.org>

W dniu 09.11.2010 11:53, Mauro Carvalho Chehab pisze:
> Em 25-10-2010 15:59, Maciej Szmigiero escreveu:
>> +			printk(KERN_NOTICE "%s DVB-T demod i2c gate was left"
>> +						    " closed\n", dev->name);
>> +			printk(KERN_NOTICE "%s previous informational"
>> +					    " EEPROM read might have been"
>> +					    " corrupted\n", dev->name);
> 
> hmm... I don't think we need those debug messages on normal cases. 

I added this message because when the gate was left closed the eeprom content (printed out unconditionally in saa7134_i2c_eeprom) looks garbled in dmesg,
so it's better to inform user that he (or she) shouldn't be worried about this.
The eeprom dump is called from saa7134_i2c_register, before card-specific code has opportunity to run.

>>  	saa7134_tuner_setup(dev);
>>  
>> +	/* some cards (Medion 7134 for example) needs tuner to be setup */
>> +	/* before tda9887 shows itself on i2c bus */
>> +	if ((TUNER_ABSENT != dev->tuner_type)
>> +			&& (dev->tda9887_conf & TDA9887_PRESENT)) {
>> +		v4l2_i2c_new_subdev(&dev->v4l2_dev,
>> +			&dev->i2c_adap, "tuner", "tuner",
>> +			0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
>> +	}
>> +
>>  	switch (dev->board) {
>>  	case SAA7134_BOARD_BEHOLD_COLUMBUS_TVFM:
>>  	case SAA7134_BOARD_AVERMEDIA_CARDBUS_501:
> 
> The order change for the demod probe will likely break support for other boards.
> If the problem is specific to Medion 7134, what you should do, instead, is to
> change the order just for MD7134 (so, inside the switch(dev->board)).

It was done in that order (tuner first then tda9887) for a long time before it was changed.
For example ( http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=drivers/media/video/saa7134/saa7134-core.c;hb=7a766f9ddd74b50d6069f054a3004ece0439f5c1 ) it used to look like that:
 942         /* load i2c helpers */
 943         if (TUNER_ABSENT != dev->tuner_type)
 944                 request_module("tuner");
 945         if (dev->tda9887_conf)
 946                 request_module("tda9887");
 947         if (card_is_empress(dev)) {
 948                 request_module("saa6752hs");
 949                 request_module_depend("saa7134-empress",&need_empress);
 950         }

But then the code for tda9887 was integrated into tuner module and later split out again, this time reversing the detection order (by accident I suppose).
 
> Cheers,
> Mauro.
> 

Best regards,
Maciej Szmigiero

      reply	other threads:[~2010-11-09 15:02 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-25 17:59 [V4L][SAA7134] fix tda9887 detection on cold and eeprom read corruption on warm Medion 7134 Maciej Szmigiero
2010-11-09 10:53 ` Mauro Carvalho Chehab
2010-11-09 15:02   ` Maciej Szmigiero [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4CD96294.8010905@o2.pl \
    --to=mhej@o2.pl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=mchehab@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox