Return-path: Received: from compulab.co.il ([67.18.134.219]:47693 "EHLO compulab.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752311Ab0HVNWz (ORCPT ); Sun, 22 Aug 2010 09:22:55 -0400 Message-ID: <4C712480.1090006@compulab.co.il> Date: Sun, 22 Aug 2010 16:22:08 +0300 From: Mike Rapoport MIME-Version: 1.0 To: Marek Vasut CC: libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, rusty@rustcorp.com.au, Mike Rapoport Subject: Re: [PATCH] libertas: if_sdio: fix buffer alignment in struct if_sdio_card References: <1282476160-6913-1-git-send-email-mike@compulab.co.il> <201008221459.25574.marek.vasut@gmail.com> In-Reply-To: <201008221459.25574.marek.vasut@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: Marek Vasut wrote: > Dne Ne 22. srpna 2010 13:22:40 Mike Rapoport napsal(a): >> The commit 886275ce41a9751117367fb387ed171049eb6148 (param: lock >> if_sdio's lbs_helper_name and lbs_fw_name against sysfs changes) >> introduced new fields into the if_sdio_card structure. It caused >> missalignment of the if_sdio_card.buffer field and failure at driver >> load time: >> >> ~# modprobe libertas_sdio >> [ 62.315124] libertas_sdio: Libertas SDIO driver >> [ 62.319976] libertas_sdio: Copyright Pierre Ossman >> [ 63.020629] DMA misaligned error with device 48 >> [ 63.025207] mmci-omap-hs mmci-omap-hs.1: unexpected dma status 800 >> [ 66.005035] libertas: command 0x0003 timed out >> [ 66.009826] libertas: Timeout submitting command 0x0003 >> [ 66.016296] libertas: PREP_CMD: command 0x0003 failed: -110 >> >> Adding explicit alignment attribute for the if_sdio_card.buffer field >> fixes this problem. >> >> Signed-off-by: Mike Rapoport >> --- >> drivers/net/wireless/libertas/if_sdio.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/net/wireless/libertas/if_sdio.c >> b/drivers/net/wireless/libertas/if_sdio.c index ba854c7..87b6349 100644 >> --- a/drivers/net/wireless/libertas/if_sdio.c >> +++ b/drivers/net/wireless/libertas/if_sdio.c >> @@ -128,7 +128,7 @@ struct if_sdio_card { >> bool helper_allocated; >> bool firmware_allocated; >> >> - u8 buffer[65536]; >> + u8 buffer[65536] __attribute__((aligned(4))); >> >> spinlock_t lock; >> struct if_sdio_packet *packets; > > Will this work even on platforms that need some weird DMA destination address > alignment ? I might be totally off with this question though ;-) I've tested it on PXA and OMAP and it works on both. I think that on platforms with weird DMA destination address alignment libertas_sdio will fail anyway because of if_sdio_packet alignment. > Cheers > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Sincerely yours, Mike.