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:[email protected]] > >>> Sent: Friday, September 25, 2015 2:37 PM > >>> To: Rob Groner <[email protected]> > >>> Cc: [email protected]; [email protected] > >>> 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: [email protected] [mailto:[email protected]] > >>>>> Sent: Friday, September 25, 2015 12:48 PM > >>>>> To: Rob Groner <[email protected]> > >>>>> Cc: [email protected] > >>>>> 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://www.exar.com/common/content/document.ashx?id=20121
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 _______________________________________________ Kernelnewbies mailing list [email protected] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
