[SLOF] [PATCH v2 1/2] usb/storage: Invert the logic of the IF-statements

[Laurent Vivier]

On 12/12/2018 20:23, Thomas Huth wrote:
> On 2018-12-12 15:31, Laurent Vivier wrote:
>> to prepare write implementation
>>
>> Signed-off-by: Laurent Vivier <lvivier at redhat.com>
>> ---
>>  slof/fs/usb/dev-storage.fs | 39 +++++++++++++++++++-------------------
>>  1 file changed, 19 insertions(+), 20 deletions(-)
>>
>> diff --git a/slof/fs/usb/dev-storage.fs b/slof/fs/usb/dev-storage.fs
>> index 94f8421..fe5af1c 100644
>> --- a/slof/fs/usb/dev-storage.fs
>> +++ b/slof/fs/usb/dev-storage.fs
>> @@ -107,23 +107,23 @@ scsi-open
>>      TO resp-size
>>      TO resp-buffer
>>      udev USB_PIPE_OUT td-buf td-buf-phys dma-buf-phys usb>cmd 1F
>> -    usb-transfer-bulk IF \ transfer CBW
>> -	resp-size IF
>> -	    d# 125 us
>> -	    udev USB_PIPE_IN td-buf td-buf-phys resp-buffer resp-size
>> -	    usb-transfer-bulk 1 = not IF \ transfer data
>> -	        usb-disk-debug?	IF ." Data phase failed " cr THEN
>> -		\ FALSE EXIT
>> -		\ in case of a stall/halted endpoint we clear the halt
>> -		\ Fall through and try reading the CSW
>> -	    THEN
>> -	THEN
>> -	d# 125 us
>> -	udev USB_PIPE_IN td-buf td-buf-phys dma-buf-phys usb>csw 0D
>> -	usb-transfer-bulk \ transfer CSW
>> -    ELSE
>> -	FALSE EXIT
>> +    usb-transfer-bulk 1 = not IF
> 
> In case you respin: Replace "= not" with "<>".
> (sorry for not noticing this in v1 already!)
> 
>> +        FALSE EXIT
>>      THEN
>> +    \ transfer CBW
>> +    resp-size IF
>> +        d# 125 us
>> +        udev USB_PIPE_IN td-buf td-buf-phys resp-buffer resp-size
>> +        usb-transfer-bulk 1 = not IF \ transfer data
> 
> You only moved the code, but in case you respin, "= not" could be
> replaced with "<>" here, too.
> 
>> +            usb-disk-debug? IF ." Data phase failed " cr THEN
>> +            \ FALSE EXIT
>> +            \ in case of a stall/halted endpoint we clear the halt
>> +            \ Fall through and try reading the CSW
>> +        THEN
>> +    THEN
>> +    d# 125 us
>> +    udev USB_PIPE_IN td-buf td-buf-phys dma-buf-phys usb>csw 0D
>> +    usb-transfer-bulk \ transfer CSW
>>  ;
>>  
>>  STRUCT \ cbw
>> @@ -189,12 +189,11 @@ CONSTANT cbw-length
>>  
>>      \ Send it
>>      dma-buf-phys usb>data usb-buf-len
>> -    do-bulk-command IF
>> -	dma-buf usb>data usb-buf-addr usb-buf-len move
>> -    ELSE
>> -        ." USB-DISK: Bulk commad failed!" cr
>> +    do-bulk-command 1 = not IF
> 
> "= not" ==> "<>"
> 
> Or maybe you could even simply say:
> 
>   do-bulk-command not IF
> 
> ... since the C functions are simply returning "bool"s - and the
> IF-statement in Forth does not care whether the "true" value on the
> stack is -1 or 1.

... but "not" doesn't like it:

0 > 0 not .  -1  ok
0 > 1 not .  -2  ok
0 > -1 not .  0  ok


I'm going to change the "=" by "<>" in the series.

Thanks,
Laurent