Messages in this thread | | | Date | Mon, 16 Mar 2015 22:37:18 +0100 (CET) | From | Jiri Kosina <> | Subject | Re: [PATCH] HID: sony: Enable Gasia third-party PS3 controllers |
| |
On Mon, 16 Mar 2015, Pavel Machek wrote:
> > > Oliver Neukum <oneukum@suse.de> wrote: > > > > > > > > + ret = usb_interrupt_msg(dev, usb_sndintpipe(dev, 0x02), > > > > > + buf2, sizeof(buf2), > > > > > + &transfered, USB_CTRL_SET_TIMEOUT); > > > > > > > > You cannot do this. Even for a single byte DMA on the stack is > > > > wrong. Not on all architectures it works at all and you violate > > > > the DMA constrainsts. You must use kmalloc(). > > > > > > Hi Oliver, > > > > > > Does this still apply when using hid_hw_output_report? > > > > Yes. For USB devices hid_hw_output_report() goes to > > usbhid_output_report(). That goes to usb_interrupt_msg(), > > which passes the buffer pointer. It will then be mapped > > for DMA. You must not do that on the stack. > > Should we have some kind of runtime test for this ...? Because this is > very very easy to get wrong... and I bet we do get it wrong at > 1 > place...
Are you sure CONFIG_DMA_API_DEBUG wouldn't warn here?
-- Jiri Kosina SUSE Labs
| |