> -----Original Message----- > From: Greg KH [mailto:greg@xxxxxxxxx] > Sent: Wednesday, November 11, 2015 12:32 PM > To: Rob Groner <rgroner@xxxxxxx> > Cc: kernelnewbies@xxxxxxxxxxxxxxxxx > Subject: Re: [PATCH] 8250_pci: Prevent Exar/RTD Boards from binding. > > On Wed, Nov 11, 2015 at 03:46:23PM +0000, Rob Groner wrote: > > > > > -----Original Message----- > > > From: kernelnewbies-bounces@xxxxxxxxxxxxxxxxx > [mailto:kernelnewbies- > > > bounces@xxxxxxxxxxxxxxxxx] On Behalf Of Rob Groner > > > Sent: Monday, October 26, 2015 8:28 AM > > > To: Greg KH <greg@xxxxxxxxx> > > > Cc: kernelnewbies@xxxxxxxxxxxxxxxxx > > > Subject: RE: [PATCH] 8250_pci: Prevent Exar/RTD Boards from binding. > > > > > > > -----Original Message----- > > > > From: Greg KH [mailto:greg@xxxxxxxxx] > > > > Sent: Monday, September 28, 2015 10:12 AM > > > > To: Rob Groner <rgroner@xxxxxxx> > > > > Cc: Valdis.Kletnieks@xxxxxx; kernelnewbies@xxxxxxxxxxxxxxxxx > > > > Subject: Re: [PATCH] 8250_pci: Prevent Exar/RTD Boards from binding. > > > > > > > > On Mon, Sep 28, 2015 at 08:53:49AM -0400, Rob Groner wrote: > > > > > On Fri, 2015-09-25 at 17:45 -0700, Greg KH wrote: > > > > > > On Fri, Sep 25, 2015 at 03:21:46PM -0400, Rob Groner wrote: > > > > > > > > > > > > > > On 09/25/2015 03:14 PM, Greg KH wrote: > > > > > > > > On Fri, Sep 25, 2015 at 07:08:32PM +0000, Rob Groner wrote: > > > > > > > >>> -----Original Message----- > > > > > > > >>> From: Greg KH [mailto:greg@xxxxxxxxx] > > > > > > > >>> Sent: Friday, September 25, 2015 2:37 PM > > > > > > > >>> To: Rob Groner <rgroner@xxxxxxx> > > > > > > > >>> Cc: Valdis.Kletnieks@xxxxxx; > > > > > > > >>> kernelnewbies@xxxxxxxxxxxxxxxxx > > > > > > > >>> Subject: Re: [PATCH] 8250_pci: Prevent Exar/RTD Boards > > > > > > > >>> from > > > > binding. > > > > > > > >>> > > > > > > > >>> On Fri, Sep 25, 2015 at 05:37:03PM +0000, Rob Groner wrote: > > > > > > > >>>>> -----Original Message----- > > > > > > > >>>>> From: Valdis.Kletnieks@xxxxxx > > > > > > > >>>>> [mailto:Valdis.Kletnieks@xxxxxx] > > > > > > > >>>>> Sent: Friday, September 25, 2015 12:48 PM > > > > > > > >>>>> To: Rob Groner <rgroner@xxxxxxx> > > > > > > > >>>>> Cc: kernelnewbies@xxxxxxxxxxxxxxxxx > > > > > > > >>>>> Subject: Re: [PATCH] 8250_pci: Prevent Exar/RTD Boards > > > > > > > >>>>> from > > > > binding. > > > > > > > >>>>> > > > > > > > >>>>> On Fri, 25 Sep 2015 11:46:29 -0400, Rob Groner said: > > > > > > > >>>>>> Serial boards made by RTD using the Exar XR17V358 > > > > > > > >>>>>> chip rely on the extra capabilities of the > > > > > > > >>>>>> Exar-provided driver to allow configuration of the > > > > > > > >>>>>> board. When support for the Exar chip was added to > > > > > > > >>>>>> the kernel 8250_pci driver, this then prevented easy > > > > > > > >>>>>> use of the board by customers for anything other than > > > > > > > >>>>>> standard serial usage > > > > > > > >>> in RS232 mode. > > > > > > > >>>>> Was it your intent to also prevent the use of this > > > > > > > >>>>> board in standard serial usage in RS232 mode (which > > > > > > > >>>>> I'd expect is the most common use > > > > > > > >>> case)? > > > > > > > >>>> That is a byproduct of giving the non-average user the > > > > > > > >>>> ability to reconfigure their board. This will > > > > > > > >>>> basically move us back to pre-3.8, where the customer > > > > > > > >>>> would simply have to insmod the provided Exar driver. > > > > > > > >>>> The small inconvenience to that more common user seems > > > > > > > >>>> (to us in Tech > > > > > > > >>>> Support) outweighed by the much greater inconvenience > > > > > > > >>>> to the user who > > > > wants to reconfigure. > > > > > > > >>> Where is the exar driver, in the kernel already? > > > > > > > >>> > > > > > > > >>> confused, > > > > > > > >> I'm sorry for the confusion. Let me summup: > > > > > > > >> > > > > > > > >> We produce a serial port board that uses the Exar XR17V358 > chip. > > > > The board features a jumperless configuration so that to change > > > > the board from RS232 to RS422/RS485, you use the GPIO available on > > > > the Exar chip, via the Exar driver. That driver is provided by > > > > Exar (from their website, and repackaged on our website and with the > board). > > > > > > > >> > > > > > > > >> Recently, we began to hear from customers who purchased > > > > > > > >> the > > > > board but could not get the driver to find the board (and thus > > > > could not reconfigure it, nor use the non-standard high baud rates > > > > the chip is capable of). We discovered that in 3.8, support for > > > > the Exar chip was added to the 8250_pci driver, thus binding it to the > kernel. > > > > > > > >> > > > > > > > >> Until (and probably if) Exar decides to submit their > > > > > > > >> driver to the > > > > kernel, then it leaves us with a problem that we didn't have prior > > > > to 3.8...namely that the board won't do what it is advertised to > > > > do unless the customer rebuilds the kernel (that is the only > > > > supported workaround from Exar). The only other workaround we > > > > know of (unbind) has met with mixed success which I won't go into > > > > unless you want me to, and is already resisted by some customers. > > > > > > > >> > > > > > > > >> The goal of this patch is to get to a point where a > > > > > > > >> customer can install > > > > Linux and have full use of this RTD board (using the driver > > > > Exar/RTD provides). No one who has an RTD board is going to feel > > > > this is an inconvenience. > > > > > > > > Can you point me at the driver and I'll be glad to add it > > > > > > > > to the kernel so that the proper driver will bind to the > > > > > > > > device and this will not be an issue for users? > > > > > > > > > > > > > > > > thanks, > > > > > > > > > > > > > > > > greg k-h > > > > > > > That would be WONDERFUL. > > > > > > > > > > > > > > https://na01.safelinks.protection.outlook.com/?url=https%3a% > > > > > > > 2f%2 > > > > > > > > > > > fwww.exar.com%2fcommon%2fcontent%2fdocument.ashx%3fid%3d20121& > > > da > > > > > > > > > > > ta=01%7c01%7crgroner%40rtd.com%7c261e5150b71d4b17e91308d2de03148 > > > > > > > > > > > e%7c16f82b7977b8423dbafdd6c19032e267%7c0&sdata=Tl%2br4Vjgut%2bRh > > > > > > > 3nam6wTMwbpBDpqIW%2fb2dzsTJtE0A4%3d > > > > > > > > > > > > At first glance, the driver looks pretty good. Let me do a > > > > > > bit of cleanup on it for mostly coding style changes and > > > > > > removing some old api support and see what the patch is. > > > > > > > > > > > > Would you mind testing it if I make a patch, given that I > > > > > > don't have the hardware and you do? :) > > > > > > > > > > > > thanks, > > > > > > > > > > > > greg k-h > > > > > > > > > > I don't mind in the slightest, it's the least I can do! I've > > > > > got my test station ready and have 3 different CPUs I can test > > > > > with. Being new to the whole patching thing, I may need a few > > > > > hints and helps to make sure I apply the patch correctly... > > > > > > > > > > Will it be showing up here in kernel newbies mailing list, or > > > > > linux-serial, or other? > > > > > > > > How about let's take it to linux-serial, and I'll cc: you as well, > > > > that's the proper place for this. > > > > > > > > Note, the driver does do some "odd" things in that it has some > "custom" > > > > ioctls for unknown reasons, and it grabs a major number of another > > > > driver, both things that I can't accept upstream. It also seems > > > > to duplicate a lot of existing code, so maybe it doesn't really > > > > need to be a separate driver. I'll dig around in it and see what > > > > I can come up with, > > > give me a week or so... > > > > > > > > thanks, > > > > > > > > greg k-h > > > > > > I know you're incredibly busy, so I added as much "so" to the week as I > could. > > > Any way I can help with this endeavor, other than testing? > > > > Would it be possible to consider my original patch, if putting in the Exar > driver is too time consuming? > > I'd rather have the Exar driver than my patch, but I'd also rather have my > patch than the current situation. > > I don't remember what your "original patch" was, sorry. > > greg k-h My patch prevented RTD-subvendor boards that have the Exar serial chip on them from being bound to the kernel 8250_pci driver. That allows our customers to insert the Exar-provided driver which then gives them access to configuring the board. You asked for a link to the Exar driver, and you graciously offered to put the driver into the kernel, which would also solve our problem. Thank you, Rob G. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
