From: Alan Mikhak <alan.mikhak@xxxxxxxxxx> Modify dw_edma_irq_request() to check if a struct msi_desc entry exists before copying the contents of its struct msi_msg pointer. Without this sanity check, __get_cached_msi_msg() crashes when invoked by dw_edma_irq_request() running on a Linux-based PCIe endpoint device. MSI interrupt are not received by PCIe endpoint devices. If irq_get_msi_desc() returns null, then there is no cached struct msi_msg to be copied. This patch depends on the following patch: [PATCH v2] dmaengine: dw-edma: Decouple dw-edma-core.c from struct pci_dev https://patchwork.kernel.org/patch/11491757/ Signed-off-by: Alan Mikhak <alan.mikhak@xxxxxxxxxx> --- drivers/dma/dw-edma/dw-edma-core.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c index db401eb11322..a5d15f6ed5eb 100644 --- a/drivers/dma/dw-edma/dw-edma-core.c +++ b/drivers/dma/dw-edma/dw-edma-core.c @@ -773,6 +773,7 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip, u32 rd_mask = 1; int i, err = 0; u32 ch_cnt; + int irq; ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt; @@ -781,16 +782,16 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip, if (dw->nr_irqs == 1) { /* Common IRQ shared among all channels */ - err = request_irq(dw->ops->irq_vector(dev, 0), - dw_edma_interrupt_common, + irq = dw->ops->irq_vector(dev, 0); + err = request_irq(irq, dw_edma_interrupt_common, IRQF_SHARED, dw->name, &dw->irq[0]); if (err) { dw->nr_irqs = 0; return err; } - get_cached_msi_msg(dw->ops->irq_vector(dev, 0), - &dw->irq[0].msi); + if (irq_get_msi_desc(irq)) + get_cached_msi_msg(irq, &dw->irq[0].msi); } else { /* Distribute IRQs equally among all channels */ int tmp = dw->nr_irqs; @@ -804,7 +805,8 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip, dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt); for (i = 0; i < (*wr_alloc + *rd_alloc); i++) { - err = request_irq(dw->ops->irq_vector(dev, i), + irq = dw->ops->irq_vector(dev, i); + err = request_irq(irq, i < *wr_alloc ? dw_edma_interrupt_write : dw_edma_interrupt_read, @@ -815,8 +817,8 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip, return err; } - get_cached_msi_msg(dw->ops->irq_vector(dev, i), - &dw->irq[i].msi); + if (irq_get_msi_desc(irq)) + get_cached_msi_msg(irq, &dw->irq[i].msi); } dw->nr_irqs = i; -- 2.7.4
