On Thu, Jul 18, 2019 at 09:54:42PM -0500, Navid Emamdoost wrote: > pci_ioremap_bar may return null. This is eventually de-referenced at > drivers/dma/dw/core.c:1154 and drivers/dma/dw/core.c:1168. A null check is > needed to prevent null de-reference. I am adding the check and in case of > failure returning -ENOMEM (I am not sure this is the best errno, you may > consider it as a placeholder), and subsequently changing the caller’s > return type, and propagating the error. Thanks for the patch, my comments below. > chip->irq = pci_irq_vector(pdev, 0); > chip->regs = pci_ioremap_bar(pdev, 1); > + if (!chip->regs) > + return -ENOMEM; This is the same case as below, it's fine to go on without DMA support. > chip->pdata = &qrk_serial_dma_pdata; So, I would rather to put like this... Hold on, I remember someone already tried to fix this [1]. I dunno why it wasn't v5, due to [2]. Also, similar to yours, but wrong [3]. Thus, please, collaborate guys, and send one compiling solution based on [1]. > /* Falling back to PIO mode if DMA probing fails */ > ret = dw_dma_probe(chip); > if (ret) > - return; > + return 0; [1]: https://www.spinics.net/lists/linux-serial/msg33965.html [2]: https://lists.01.org/pipermail/kbuild-all/2019-March/059215.html [3]: https://lore.kernel.org/patchwork/patch/1051000/ -- With Best Regards, Andy Shevchenko
