From: David Brownell <david-b@pacbell•net>
To: Grant Likely <grant.likely@secretlab•ca>
Cc: akpm@osdl•org, linuxppc-dev@ozlabs•org, gregkh@suse•de,
linux-usb-devel@lists•sourceforge.net
Subject: Re: [PATCH 1/5] USB: Make usb_hcd_irq work for multi-role USB controllers w/ shared irq
Date: Sat, 24 Nov 2007 11:06:46 -0800 [thread overview]
Message-ID: <200711241106.46515.david-b@pacbell.net> (raw)
In-Reply-To: <20071124002431.25361.23974.stgit@trillian.cg.shawcable.net>
On Friday 23 November 2007, Grant Likely wrote:
> Some multi-role (host/peripheral) USB controllers use a shared interrupt
> line for all parts of the chip.
Like the musb_hdrc code ... soonish to go upstream (it needs some
updates to catch up to usbcore urb->status changes), this is used
by the Nokia 800 and 810. In terms of chips with Linux support:
DaVinci, TUSB60x0, OMAP 2430, OMAP 3430, Blackfin BF527; and ISTR
a few less-publicised ones (including, yes, some PPC SOCs).
That driver hasn't needed to change usbcore for IRQ handling though.
> Export usb_hcd_irq so drivers can call it
> from their interrupt handler instead of duplicating code.
This seems to be the main point of this patch. I'd rather just
make that "static" though; it should already be marked that way.
That routine doesn't do enough to make me like it any more; and
with dual-role controllers, the driver lifecycle is more complex
than usbcore can be expected to mediate. Best to just call the
host side IRQ logic directly from your toplevel IRQ handler.
> Drivers pass an irqnum of 0 to usb_add_hcd to signal that the interrupt handler
> shouldn't be registerred by the core.
The current way to get that behavior is to leave hcd->driver->irq
as zero; then "irqnum" is ignored, and your dual role driver can
register its own handler.
- Dave
next prev parent reply other threads:[~2007-11-24 19:06 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-24 0:24 [PATCH 0/5] Review request: Cypress c67x00 OTG controller Grant Likely
2007-11-24 0:24 ` [PATCH 1/5] USB: Make usb_hcd_irq work for multi-role USB controllers w/ shared irq Grant Likely
2007-11-24 5:10 ` Greg KH
2007-11-24 17:03 ` [linux-usb-devel] " Alan Cox
2007-11-24 17:15 ` Grant Likely
2007-11-24 17:50 ` David Brownell
2007-11-24 19:06 ` David Brownell [this message]
2007-11-24 19:28 ` Grant Likely
2007-11-24 0:24 ` [PATCH 2/5] USB: Add Cypress c67x00 low level interface code Grant Likely
2007-11-24 19:39 ` David Brownell
2007-11-24 0:24 ` [PATCH 3/5] USB: add Cypress c67x00 OTG controller core driver Grant Likely
2007-11-24 0:24 ` [PATCH 4/5] USB: add Cypress c67x00 OTG controller HCD driver Grant Likely
2007-11-24 3:56 ` [linux-usb-devel] " Alan Stern
2007-11-24 0:24 ` [PATCH 5/5] USB: Add Cypress c67x00 OTG controller driver to Kconfig and Makefiles Grant Likely
2007-11-24 20:12 ` David Brownell
2007-11-24 20:20 ` Grant Likely
2007-11-24 21:03 ` David Brownell
2007-11-24 21:13 ` Grant Likely
2007-11-24 17:57 ` [PATCH 0/5] Review request: Cypress c67x00 OTG controller David Brownell
2007-11-24 19:27 ` Grant Likely
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