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* USB transfer_buffer allocations on 64bit systems
@ 2010-04-07  9:06 Daniel Mack
       [not found] ` <p2g581ef6d61004070220z1153d40ez955b356e01220848@mail.gmail.com>
  2010-04-07 14:59 ` USB transfer_buffer allocations on 64bit systems Alan Stern
  0 siblings, 2 replies; 90+ messages in thread
From: Daniel Mack @ 2010-04-07  9:06 UTC (permalink / raw)
  To: linux-kernel
  Cc: alsa-devel, linux-usb, Greg KH, Alan Stern, Pedro Ribeiro, akpm

Hi,

I was pointed to https://bugzilla.kernel.org/show_bug.cgi?id=15580 by
Pedro Ribeiro, and unfortunately I'm pretty late in the game. I wasn't
aware of that thread until yesterday.

While the report is quite confusing, the reason seams pretty clear to me
as I've been thru quite some time-demanding debugging of a very similar
issue on Mac OS X. But I'm not totally sure whether we really hit the
same issue here, so I'd like to have your opinions first.

The problem is appearantly the way the transfer buffer is allocated in
the drivers. In the snd-usb-caiaq driver, I used kzalloc() to get memory
which works fine on 32bit systems. On x86_64, however, it seems that
kzalloc() hands out memory beyond the 32bit addressable boundary, which
the DMA controller of the 32bit PCI-connected EHCI controller is unable
to write to or read from. Am I correct on this conclusion?

Depending on the condition of the memory management, things might work
or not, and especially right after a reboot, there's a better chance to
get lower memory.

The fix is to use usb_buffer_alloc() for that purpose which ensures
memory that is suitable for DMA. And on x86_64, this also means that the
upper 32 bits of the address returned are all 0's.

If what I've stated is true, there are quite some more drivers affected
by this issue. I collected a list of places where similar fixes are
needed, and I can send patches if I get a thumbs-up.

Pedro is currently testing a patch I sent out yesterday.

Thanks,
Daniel

^ permalink raw reply	[flat|nested] 90+ messages in thread

end of thread, other threads:[~2010-04-15  7:35 UTC | newest]

Thread overview: 90+ messages (download: mbox.gz follow: Atom feed
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2010-04-07  9:06 USB transfer_buffer allocations on 64bit systems Daniel Mack
     [not found] ` <p2g581ef6d61004070220z1153d40ez955b356e01220848@mail.gmail.com>
2010-04-07  9:26   ` USB HID gadget driver (was: Re: USB transfer_buffer allocations on 64bit systems) Daniel Mack
2010-04-07 14:59 ` USB transfer_buffer allocations on 64bit systems Alan Stern
2010-04-07 15:11   ` Daniel Mack
2010-04-07 15:31     ` Greg KH
2010-04-07 15:35       ` Daniel Mack
2010-04-07 15:51         ` Greg KH
     [not found]           ` <20100407155122.GA13974-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2010-04-07 16:04             ` Alan Stern
2010-04-08  6:09         ` Oliver Neukum
     [not found]           ` <201004080809.11756.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
2010-04-08 11:07             ` Daniel Mack
2010-04-07 15:55       ` Alan Stern
2010-04-07 16:16         ` Daniel Mack
2010-04-07 16:47           ` Alan Stern
2010-04-07 17:55           ` Takashi Iwai
2010-04-07 17:59             ` Daniel Mack
2010-04-07 18:06               ` Takashi Iwai
2010-04-07 19:13             ` Alan Stern
2010-04-08  0:33               ` Greg KH
2010-04-09  0:01                 ` Robert Hancock
     [not found]                   ` <4BBE6E57.6020600-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2010-04-09 16:50                     ` Sarah Sharp
2010-04-09 23:38                       ` Robert Hancock
2010-04-10  8:34                         ` Daniel Mack
2010-04-10 17:02                           ` [alsa-devel] " Robert Hancock
2010-04-12 18:56                             ` Sarah Sharp
2010-04-12 20:39                               ` Robert Hancock
2010-04-12 20:58                                 ` Sarah Sharp
     [not found]               ` <Pine.LNX.4.44L0.1004071452560.5760-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-04-07 23:59                 ` Robert Hancock
2010-04-12 11:17                 ` [PATCH] USB: rename usb_buffer_alloc() and usb_buffer_free() Daniel Mack
     [not found]                   ` <1271071045-3112-1-git-send-email-daniel-rDUAYElUppE@public.gmane.org>
2010-04-13 18:16                     ` Daniel Mack
     [not found]                       ` <20100413181631.GT30801-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-13 19:27                         ` Alan Stern
2010-04-13 20:26                           ` Greg KH
2010-04-13 21:47                             ` Daniel Mack
2010-04-07 17:52         ` USB transfer_buffer allocations on 64bit systems Takashi Iwai
2010-04-07 15:46     ` Alan Stern
2010-04-08  6:12       ` Oliver Neukum
     [not found]         ` <201004080812.04419.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
2010-04-08 16:59           ` Alan Stern
2010-04-08 21:24             ` Oliver Neukum
2010-04-08 22:20               ` Alan Stern
2010-04-09  6:04                 ` Oliver Neukum
     [not found]                   ` <201004090804.36213.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
2010-04-09 14:41                     ` Alan Stern
     [not found]                       ` <Pine.LNX.4.44L0.1004091033150.1852-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-04-09 14:50                         ` Oliver Neukum
     [not found]                           ` <201004091650.31488.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
2010-04-09 15:15                             ` Alan Stern
     [not found]                               ` <Pine.LNX.4.44L0.1004091114500.1852-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-04-09 20:51                                 ` Oliver Neukum
2010-04-09 21:21                                   ` Alan Stern
     [not found]   ` <Pine.LNX.4.44L0.1004071036060.1779-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-04-07 16:54     ` Oliver Neukum
     [not found]       ` <201004071854.55530.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
2010-04-07 17:00         ` Daniel Mack
2010-04-07 23:55     ` Robert Hancock
     [not found]       ` <4BBD1B6F.3000205-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2010-04-08  2:10         ` Alan Stern
2010-04-08  7:30           ` Daniel Mack
     [not found]             ` <20100408073041.GO30801-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-08 16:57               ` Alan Stern
2010-04-08 17:17                 ` Pedro Ribeiro
     [not found]                 ` <Pine.LNX.4.44L0.1004081245330.1720-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-04-08 23:13                   ` Pedro Ribeiro
2010-04-09 16:01                     ` Alan Stern
2010-04-09 18:09                       ` Daniel Mack
     [not found]                         ` <20100409180942.GK30801-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-09 18:19                           ` Pedro Ribeiro
     [not found]                             ` <w2r74fd948d1004091119j9f33d8a6kc1824d9243abf38b-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-04-09 19:34                               ` Alan Stern
2010-04-09 20:14                                 ` Daniel Mack
     [not found]                                 ` <Pine.LNX.4.44L0.1004091529240.1852-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-04-09 20:25                                   ` [LKML] " Konrad Rzeszutek Wilk
     [not found]                                     ` <20100409202533.GA8983-6K5HmflnPlqSPmnEAIUT9EEOCMrvLtNR@public.gmane.org>
2010-04-09 21:23                                       ` Alan Stern
2010-04-09 22:11                                         ` Robert Hancock
2010-04-12 10:48                                           ` Daniel Mack
2010-04-12 12:06                                             ` Pedro Ribeiro
2010-04-10 12:49                             ` Daniel Mack
     [not found]                               ` <20100410124912.GP30801-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-10 13:21                                 ` Pedro Ribeiro
2010-04-12  8:59   ` Andi Kleen
2010-04-12 11:14     ` Daniel Mack
     [not found]       ` <20100412111439.GU30801-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-12 11:53         ` Andi Kleen
2010-04-12 12:11           ` Pedro Ribeiro
     [not found]             ` <q2z74fd948d1004120511hebf19eaauc41ee9ed25dea19e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-04-12 12:12               ` Andi Kleen
2010-04-12 12:32                 ` Daniel Mack
2010-04-12 12:47                   ` Andi Kleen
2010-04-12 12:54                     ` Daniel Mack
2010-04-12 15:43                       ` Andi Kleen
     [not found]                         ` <20100412154323.GP18855-qrUzlfsMFqo/4alezvVtWx2eb7JE58TQ@public.gmane.org>
2010-04-12 16:17                           ` Alan Stern
2010-04-12 16:29                             ` Andi Kleen
2010-04-12 16:57                               ` Alan Stern
2010-04-12 17:15                                 ` Daniel Mack
     [not found]                                   ` <20100412171507.GB30801-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-12 17:22                                     ` Andi Kleen
2010-04-12 17:56                                       ` Daniel Mack
2010-04-12 17:52                                     ` [LKML] " Konrad Rzeszutek Wilk
2010-04-13 18:22                                 ` Daniel Mack
     [not found]                                   ` <20100413182233.GR30807-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-13 23:46                                     ` Pedro Ribeiro
2010-04-14 10:09                                       ` Daniel Mack
2010-04-14 10:47                                         ` Pedro Ribeiro
2010-04-14 11:02                                           ` Pedro Ribeiro
2010-04-14 13:18                                           ` [LKML] " Konrad Rzeszutek Wilk
     [not found]                                           ` <t2w74fd948d1004140347k3447bffapb73856eacddfde55-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-04-14 14:08                                             ` Alan Stern
2010-04-14 16:36                                               ` Daniel Mack
     [not found]                                                 ` <20100414163637.GV30807-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org>
2010-04-14 17:21                                                   ` Pedro Ribeiro
2010-04-15  7:35                                                     ` Daniel Mack

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