lkml.org 
[lkml]   [2014]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 2/2] serial: pl011: Move uart_register_driver call to device probe
    On Thu, Feb 13, 2014 at 10:12:16AM -0800, Greg KH wrote:
    > On Mon, Jan 20, 2014 at 10:04:15AM +0000, Russell King - ARM Linux wrote:
    > > On Mon, Jan 20, 2014 at 02:32:35PM +0530, Tushar Behera wrote:
    > > > uart_register_driver call binds the driver to a specific device
    > > > node through tty_register_driver call. This should typically happen
    > > > during device probe call.
    > > >
    > > > In a multiplatform scenario, it is possible that multiple serial
    > > > drivers are part of the kernel. Currently the driver registration fails
    > > > if multiple serial drivers with same default major/minor numbers are
    > > > included in the kernel.
    > > >
    > > > A typical case is observed with amba-pl011 and samsung-uart drivers.
    > >
    > > NAK. There should not be any other driver using amba-pl011's device numbers.
    >
    > I agree, but there is. And because of that, moving the registration to
    > the probe call fixes the issue with building a kernel with all of the
    > drivers built into them, so I'm going to take both of these patches, as
    > it does solve that problem, while still allowing the device number
    > collision to happen.

    So what happens when two _devices_ are probed by this driver at the same
    time?

    --
    FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation
    in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
    Estimate before purchase was "up to 13.2Mbit".


    \
     
     \ /
      Last update: 2014-02-13 19:41    [W:3.560 / U:1.256 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site