From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH] mmc: dw_mmc: fix unmap sg twice when finding data err Date: Wed, 29 Jun 2016 10:31:06 +0900 Message-ID: <577324DA.9010703@samsung.com> References: <1466753992-13727-1-git-send-email-shawn.lin@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1466753992-13727-1-git-send-email-shawn.lin@rock-chips.com> Sender: linux-kernel-owner@vger.kernel.org To: Shawn Lin Cc: Seung-Woo Kim , Ulf Hansson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-mmc@vger.kernel.org Hi Shawn, On 06/24/2016 04:39 PM, Shawn Lin wrote: > DATA_OVER(the same for RI/TI of IDMAC) interrupt may come > up together with data error interrupts. If so, the interrupt > routine set EVENT_DATA_ERR to the pending_events and schedule > the tasklet but we may still fallback to the IDMAC interrupt > case as the tasklet may come up a little late, namely right > after the IDMAC interrupt checking. This will casue dw_mmc > unmap sg twice. We can easily see it with CONFIG_DMA_API_DEBUG > enabled. > > WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1096 check_unmap+0x7bc/0xb38 > dwmmc_exynos 12200000.mmc: DMA-API: device driver tries to free DMA memory it > has not allocated [device address=0x000000006d9d2200] > [size=128 bytes] > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.7.0-rc4 #26 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [] (unwind_backtrace) from [] (show_stack+0x20/0x24) > [] (show_stack) from [] (dump_stack+0x80/0x94) > [] (dump_stack) from [] (__warn+0xf8/0x110) > [] (__warn) from [] (warn_slowpath_fmt+0x48/0x50) > [] (warn_slowpath_fmt) from [] (check_unmap+0x7bc/0xb38) > [] (check_unmap) from [] (debug_dma_unmap_sg+0x118/0x148) > [] (debug_dma_unmap_sg) from [] (dw_mci_dma_cleanup+0x7c/0xb8) > [] (dw_mci_dma_cleanup) from [] (dw_mci_stop_dma+0x40/0x50) > [] (dw_mci_stop_dma) from [] (dw_mci_tasklet_func+0x130/0x3b4) > [] (dw_mci_tasklet_func) from [] (tasklet_action+0xb4/0x150) > [] (tasklet_action) from [] (__do_softirq+0xe4/0x3cc) > [] (__do_softirq) from [] (irq_exit+0xd0/0x10c) > [] (irq_exit) from [] (__handle_domain_irq+0x90/0xfc) > [] (__handle_domain_irq) from [] (gic_handle_irq+0x64/0xa8) > [] (gic_handle_irq) from [] (__irq_svc+0x54/0x90) > Exception stack(0xc1101ef8 to 0xc1101f40) > 1ee0: 00000001 00000000 > 1f00: 00000000 c011b600 c1100000 c110753c 00000000 c11c3984 c11074d4 c1107548 > 1f20: 00000000 c1101f54 c1101f58 c1101f48 c010a1fc c010a200 60000013 ffffffff > [] (__irq_svc) from [] (arch_cpu_idle+0x48/0x4c) > [] (arch_cpu_idle) from [] (default_idle_call+0x30/0x3c) > [] (default_idle_call) from [] (cpu_startup_entry+0x358/0x3b4) > [] (cpu_startup_entry) from [] (rest_init+0x94/0x98) > [] (rest_init) from [] (start_kernel+0x3a4/0x3b0) > [] (start_kernel) from [<4000807c>] (0x4000807c) > ---[ end trace 256f83eed365daf0 ]--- > > Reported-by: Seung-Woo Kim > Signed-off-by: Shawn Lin Applied this patch on my repository. Thanks! Best Regards, Jaehoon Chung > --- > > drivers/mmc/host/dw_mmc.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 8012858..7e88541 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -2473,7 +2473,8 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id) > mci_writel(host, IDSTS64, SDMMC_IDMAC_INT_TI | > SDMMC_IDMAC_INT_RI); > mci_writel(host, IDSTS64, SDMMC_IDMAC_INT_NI); > - host->dma_ops->complete((void *)host); > + if (!test_bit(EVENT_DATA_ERROR, &host->pending_events)) > + host->dma_ops->complete((void *)host); > } > } else { > pending = mci_readl(host, IDSTS); > @@ -2481,7 +2482,8 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id) > mci_writel(host, IDSTS, SDMMC_IDMAC_INT_TI | > SDMMC_IDMAC_INT_RI); > mci_writel(host, IDSTS, SDMMC_IDMAC_INT_NI); > - host->dma_ops->complete((void *)host); > + if (!test_bit(EVENT_DATA_ERROR, &host->pending_events)) > + host->dma_ops->complete((void *)host); > } > } > >