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) [<c0112b4c>] (unwind_backtrace) from [<c010d888>] (show_stack+0x20/0x24) [<c010d888>] (show_stack) from [<c03fab0c>] (dump_stack+0x80/0x94) [<c03fab0c>] (dump_stack) from [<c0123548>] (__warn+0xf8/0x110) [<c0123548>] (__warn) from [<c01235a8>] (warn_slowpath_fmt+0x48/0x50) [<c01235a8>] (warn_slowpath_fmt) from [<c042ac90>] (check_unmap+0x7bc/0xb38) [<c042ac90>] (check_unmap) from [<c042b25c>] (debug_dma_unmap_sg+0x118/0x148) [<c042b25c>] (debug_dma_unmap_sg) from [<c077512c>] (dw_mci_dma_cleanup+0x7c/0xb8) [<c077512c>] (dw_mci_dma_cleanup) from [<c0773f24>] (dw_mci_stop_dma+0x40/0x50) [<c0773f24>] (dw_mci_stop_dma) from [<c0777d04>] (dw_mci_tasklet_func+0x130/0x3b4) [<c0777d04>] (dw_mci_tasklet_func) from [<c0129760>] (tasklet_action+0xb4/0x150) [<c0129760>] (tasklet_action) from [<c0101674>] (__do_softirq+0xe4/0x3cc) [<c0101674>] (__do_softirq) from [<c0129030>] (irq_exit+0xd0/0x10c) [<c0129030>] (irq_exit) from [<c01778a0>] (__handle_domain_irq+0x90/0xfc) [<c01778a0>] (__handle_domain_irq) from [<c0101548>] (gic_handle_irq+0x64/0xa8) [<c0101548>] (gic_handle_irq) from [<c010e3d4>] (__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 [<c010e3d4>] (__irq_svc) from [<c010a200>] (arch_cpu_idle+0x48/0x4c) [<c010a200>] (arch_cpu_idle) from [<c01669d8>] (default_idle_call+0x30/0x3c) [<c01669d8>] (default_idle_call) from [<c0166d3c>] (cpu_startup_entry+0x358/0x3b4) [<c0166d3c>] (cpu_startup_entry) from [<c0aa6ab8>] (rest_init+0x94/0x98) [<c0aa6ab8>] (rest_init) from [<c1000d58>] (start_kernel+0x3a4/0x3b0) [<c1000d58>] (start_kernel) from [<4000807c>] (0x4000807c) ---[ end trace 256f83eed365daf0 ]--- Reported-by: Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> --- 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); } } -- 2.3.7 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html