Message-ID: <47D2F23A.4020103@free.fr>
Date: Sat, 08 Mar 2008 21:08:26 +0100
From: matthieu castet <castet.matthieu@free.fr>
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To: mdharm-kernel@one-eyed-alien.net, linux-usb@vger.kernel.org,
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Subject: Re: [PATCH]  mass storage : emulation of sat scsi_pass_thru with
 ATACB
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Hi Matthew,

thanks for your comments

Matthew Dharm wrote:
> Why are you using an initializer instead of a new protocol code?
Because using a new protocol code means I need to patch all the place 
where there is a comparison between us->subclass and US_SC_SCSI.
After all I am US_SC_SCSI with a special case for ATA12 & ATA16 commands.
I don't translate all scsi to atacb (that's what does US_SC_ISD200).

> 
> Most of this should probably be moved into it's own file, just like all of
> the other protocol handlers.
Ok, I will move it in another file.
> 
> Actually, why do you even have a separate 'dispatcher' function?  Why not
> just one protocol handler function which checks the command at the top and
> calls invoke_transport there?
What do you means by having a separate 'dispatcher' function?
You means why I have 2 functions emulate_pass_thru_with_atacb and 
usb_stor_transparent_scsi_command_atacb ?
I did 2 functions for having a code more clean.

You suggest something like
void usb_stor_transparent_scsi_command_atacb(struct scsi_cmnd *srb,
                        struct us_data *us)
{
     if (srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12) {
         usb_stor_invoke_transport(srb, us);
         return;
     }
     copy emulate_pass_thru_with_atacb code here
}

> 
> Also, unless ATACB is a new standard (and I don't think it is, as the
> Cypress datasheet uses the term 'vendor specific'), then your functions
> need renaming.  Instead of 'emulate_pass_thru_with_atacb', how about
> something like 'cypress_atacb' --  since it's already a protocol handler,
> everyone already knows it's for passing commands.
But 'emulate_pass_thru_with_atacb' only handle ATA pass_thru scsi 
commands. It doesn't translate all scsi commands to atacb like 
'cypress_atacb' could suggest.
That's why I put 'usb_stor_transparent_scsi_command_atacb' saying it is 
transparent_scsi_command + atacb support.

Matthieu
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