Re: [PATCH] serial-u16550 driver. Fixes buffer blocking bug (2nd try)

[Takashi Iwai <tiwai@suse.de>]

At Tue, 02 Dec 2003 17:41:13 -0800,
Steve deRosier wrote:
> 
> Takashi,
> 
> I've completed my changes on the serial-u16550 driver.  I have 
> implemented most of your suggestions to my previous patch.  Now:
> 
> * There is a user selectable flag "droponfull".  Set to 1 and
>   any new bytes delivered to the driver after the buffer fills
>   up will be discarded until the buffer is able to flush some
>   bytes.
> * If droponfull==0 (or is not set, the default is 0), the driver
>   proceeds to block further input by not calling 
>   snd_rawmidi_transmit_ack() and aborting the attempt.  It will
>   try again later.
> * I've redone a bit of the interface for the buffer routines.  
>   This was done to support the proper blocking/non-blocking methods
>   as spelled out above, and to try to protect the buffer data a bit.  
> 
> So, if droponfull==0, we operate as originally desired (but the 
> original implementation was broken a bit and this fixes it).  If
> droponfull==1 we now discard new bytes if our buffer is full; this
> behavior fixes the driver "hang" problem we were having.
> 
> The changes should have no material effect on the "SNDRV_SERIAL_MS124W_MB"
> device, and all others should still work well, though we can only
> test with the SNDRV_SERIAL_GENERIC. 

thanks, the patch looks nice.

unfortunately, the patch was broken.  perhaps your mailer converted
tab to spaces.  so i applied it manually and committed to cvs.
i hope i didn't copy wrongly.

please test whether it works when rc2 appears.


ciao,

Takashi


-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
Does SourceForge.net help you be more productive?  Does it
help you create better code?  SHARE THE LOVE, and help us help
YOU!  Click Here: http://sourceforge.net/donate/