From: Mathias Nyman <mathias.nyman@linux.intel.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Subject: Re: [PATCH 00/27] xhci features for usb-next
Date: Thu, 23 Jul 2020 21:47:14 +0300 [thread overview]
Message-ID: <be21534d-df11-c957-43eb-e64a05a45404@linux.intel.com> (raw)
In-Reply-To: <20200723150411.GA2529859@kroah.com>
On 23.7.2020 18.04, Greg KH wrote:
> On Thu, Jul 23, 2020 at 05:45:03PM +0300, Mathias Nyman wrote:
>> Hi Greg
>>
>> This series for usb-next is almost completely about decoupling and
>> cleaning up relations between xhci, xhci debug capability (DbC),
>> and the DbC tty support.
>>
>> Real motivation behind this is to later turn DbC into a proper device
>> allowing us to bind different drivers to it, like dbctty.
>
> I don't really understand why you want to do that, but ok :)
Well to be fair loading different drivers for DbC isn't the only motivation.
Just using the Linux device model solves issues we are currently seeing
when using DbC on systems with several xHCI controllers. The original DbC
implementation didn't take this into account.
And as a bigger picture DbC is just one extended capability.
xHC controller provides a list of support extended capabilities, each one
with an ID and often a mmio region (inside xhci mmio range).
We don't handle these consistently in the xhci driver, for example
the role switch capability is currently turned into a platform device
while the DbC capability support is squashed all into the xhci driver.
Long term idea here would be to create a extended capability bus where each
capability is a device, (child of xhci device) and drivers for these match
based on the capability ID.
>
> What is that going to help with?
The option to load other drivers for the DbC capability will help other
developers to write "standard" Linux drivers that provide different interfaces
than TTY to send data over DbC.
I don't fully understand these TTY limitations myself, but there is a strong push
to implement this, and the task to provide the infrastructure for this landed
on my table.
Thanks
-Mathias
next prev parent reply other threads:[~2020-07-23 18:44 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 14:45 [PATCH 00/27] xhci features for usb-next Mathias Nyman
2020-07-23 14:45 ` [PATCH 01/27] xhci: Make debug message consistent with bus and port number Mathias Nyman
2020-07-23 14:45 ` [PATCH 02/27] xhci: dbc: Don't use generic xhci inc_deq() function for dbc Mathias Nyman
2020-07-23 14:45 ` [PATCH 03/27] xhci: Don't pass struct xhci_hcd pointer to xhci_link_seg() Mathias Nyman
2020-07-23 14:45 ` [PATCH 04/27] xhci: dbc: Don't use generic xhci erst allocation and free functions Mathias Nyman
2020-07-23 14:45 ` [PATCH 05/27] xhci: dbc: Remove dbc_dma_alloc_coherent() wrapper Mathias Nyman
2020-07-23 14:45 ` [PATCH 06/27] xhci: dbc: Remove dbc_dma_free_coherent() wrapper Mathias Nyman
2020-07-23 14:45 ` [PATCH 07/27] xhci: dbc: Add device pointer to dbc structure Mathias Nyman
2020-07-23 14:45 ` [PATCH 08/27] xhci: dbc: Use dev_info() and similar instead of xhci_info() Mathias Nyman
2020-07-23 14:45 ` [PATCH 09/27] xhci: dbc: Don't use xhci_write_64() as it takes xhci as a parameter Mathias Nyman
2020-07-23 14:45 ` [PATCH 10/27] xhci: dbc: Don't pass the xhci pointer as a parameter to xhci_dbc_init_context() Mathias Nyman
2020-07-23 14:45 ` [PATCH 11/27] xhci: dbc: Get the device pointer from dbc structure in dbc_ep_do_queue() Mathias Nyman
2020-07-23 14:45 ` [PATCH 12/27] xhci: dbc: Pass dbc pointer to endpoint init and exit functions Mathias Nyman
2020-07-23 14:45 ` [PATCH 13/27] xhci: dbc: Change to pass dbc pointer to xhci_do_dbc_stop() Mathias Nyman
2020-07-23 14:45 ` [PATCH 14/27] xhci: dbc: Pass dbc pointer to dbc_handle_xfer_event() instead of xhci_hcd pointer Mathias Nyman
2020-07-23 14:45 ` [PATCH 15/27] xhci: dbgtty: Pass dbc pointer when registering a dbctty device Mathias Nyman
2020-07-23 14:45 ` [PATCH 16/27] xhci: dbc: Pass dbc pointer to get_in/out_ep() helper functions to get endpoints Mathias Nyman
2020-07-23 14:45 ` [PATCH 17/27] xhci: dbc: Use dbc structure in the request completion instead of xhci_hcd Mathias Nyman
2020-07-23 14:45 ` [PATCH 18/27] xhci: dbc: Don't use generic xhci context allocation for dbc Mathias Nyman
2020-07-23 14:45 ` [PATCH 19/27] xhci: dbc: don't use generic xhci ring allocation functions " Mathias Nyman
2020-07-23 14:45 ` [PATCH 20/27] xhci: dbc: Pass dbc pointer to dbc memory init and cleanup functions Mathias Nyman
2020-07-23 14:45 ` [PATCH 21/27] xhci: dbc: Pass dbc pointer to dbc start and stop functions Mathias Nyman
2020-07-23 14:45 ` [PATCH 22/27] xhci: dbc: simplify dbc requests allocation and queueing Mathias Nyman
2020-07-23 14:45 ` [PATCH 23/27] xhci: dbc: remove endpoint pointers from dbc_port structure Mathias Nyman
2020-07-23 14:45 ` [PATCH 24/27] xhci: dbctty: split dbc tty driver registration and unregistration functions Mathias Nyman
2020-07-23 14:45 ` [PATCH 25/27] xhci: dbc: Add a operations structure to access driver functions Mathias Nyman
2020-07-23 14:45 ` [PATCH 26/27] xhci: dbgcap: remove dbc dependency on dbctty specific flag Mathias Nyman
2020-07-23 14:45 ` [PATCH 27/27] xhci: dbc: remove tty specific port structure from struct xhci_dbc Mathias Nyman
2020-07-23 15:04 ` [PATCH 00/27] xhci features for usb-next Greg KH
2020-07-23 18:47 ` Mathias Nyman [this message]
2020-07-24 7:06 ` Greg KH
2020-07-24 11:11 ` Mathias Nyman
2020-07-24 16:32 ` Greg KH
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