From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Subject: Re: 2.6.26-rc1 regression: ISA DMA broken (bisected) Date: Wed, 14 May 2008 12:50:56 -0600 Message-ID: <200805141250.57115.bjorn.helgaas@hp.com> References: <4823AAF2.7070102@keyaccess.nl> <482B0807.9050404@keyaccess.nl> <482B3274.2060006@keyaccess.nl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <482B3274.2060006@keyaccess.nl> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Rene Herman Cc: Takashi Iwai , Alan Cox , Linux Kernel , ALSA devel List-Id: alsa-devel@alsa-project.org On Wednesday 14 May 2008 12:41:56 pm Rene Herman wrote: > On 14-05-08 17:40, Rene Herman wrote: > > CC list trimmed as now PNP and ALSA specific. > > > Like this? With this (on top of the previous patch setting the > > dma_mask ofcourse) legacy ISA actually appears to be fine but it's > > then ISAPnP which goes bonkers again. Sigh. Getting an allocation > > failure. Don't understand why yet since pnp_alloc_dev() definitely > > sets the mask already. Will stare... > > You're in a maze of struct device *s, all alike... I was passing the > pnp_card->dev instead of the initialized pnp_dev->dev. > > And, not doing so brings out a difference between ISAPnP and legacy ISA > again insofar that legacy ISA does not consist of cards with multiple > devices. We just have the single struct device * for the ISA device. > > This therefore would be the easiest solution (and works fine) but seems > a bit of a hack. Bjorn, do you have an opinion? If I abstract things out > a bit more I might be able to do this nicer. One might on the other hand > argue that the dma_mask is going to be constant for all card devices so > might as well just use the card dev. I agree, it seems a bit of a hack to use a DMA mask from the card instead of from the device, since the driver should be programming the device to do the DMA. But I know very little about pnp_card in general, so don't attach too much weight to my opinion. > sound/{isa,oss} together with drivers/isdn/hisax/ are the only pnp_card > users. > > diff --git a/drivers/pnp/card.c b/drivers/pnp/card.c > index a762a41..a2842a7 100644 > --- a/drivers/pnp/card.c > +++ b/drivers/pnp/card.c > @@ -7,6 +7,7 @@ > #include > #include > #include > +#include > #include > #include "base.h" > > @@ -167,6 +168,9 @@ struct pnp_card *pnp_alloc_card(struct pnp_protocol *protocol, int id, char *pnp > sprintf(card->dev.bus_id, "%02x:%02x", card->protocol->number, > card->number); > > + card->dev.coherent_dma_mask = DMA_24BIT_MASK; > + card->dev.dma_mask = &card->dev.coherent_dma_mask; > + > dev_id = pnp_add_card_id(card, pnpid); > if (!dev_id) { > kfree(card); > >