On Tue, Dec 31, 2024 at 09:21:58PM +0530, Manivannan Sadhasivam wrote: > On Fri, Dec 20, 2024 at 08:23:29AM +0100, Niklas Cassel wrote: > > Platforms that do not have (one or more) dedicated IRQs for the eDMA > > need to set nr_irqs to a non-zero value in their DWC glue driver. > > > > Platforms that do have (one or more) dedicated IRQs do not need to > > initialize nr_irqs. DWC common code will automatically set nr_irqs. > > > > Since a glue driver can initialize nr_irqs, dw_pcie_edma_irq_verify() > > should verify that nr_irqs, if non-zero, is a valid value. Thus, add a > > check in dw_pcie_edma_irq_verify() to reject a negative nr_irqs value. > > > > Why can't we make dw_edma_chip::nr_irqs unsigned? dw_edma is defined in drivers/dma/dw-edma/dw-edma-core.h in struct dw_edma. struct dw_pcie (defined in drivers/pci/controller/dwc/pcie-designware.h) simply has a struct dw_edma as a struct member. If you bounce on nr_irqs in: drivers/dma/dw-edma/dw-edma-core.c and in drivers/dma/dw-edma/dw-edma-pcie.c you can see that this driver uses signed int for this everywhere. I didn't feel like refactoring a whole DMA driver. dw_pcie_edma_irq_verify() is supposed to verify that nr_irqs is either initialized to a valid value by a DWC PCIe glue driver, or that common code initializes it. If nr_irqs is initialized by a glue driver && "pci->edma.nr_irqs != ch_cnt", dw_pcie_edma_irq_verify() returns error and avoids calling dw_edma_probe(), thus it made sense for dw_pcie_edma_irq_verify() to also return error on negative nr_irqs. Kind regards, Niklas
