rsxx: Kernel Panic caused by mapping Discards (0317cd6d) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/block/rsxx/dma.c

+23 −20

Original line number	Diff line number	Diff line
		@@ -434,19 +434,21 @@ static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
		continue;
		}

		if (dma->cmd != HW_CMD_BLK_DISCARD) {
		if (dma->cmd == HW_CMD_BLK_WRITE)
		dir = PCI_DMA_TODEVICE;
		else
		dir = PCI_DMA_FROMDEVICE;

		/*
		* The function pci_map_page is placed here because we can
		* only, by design, issue up to 255 commands to the hardware
		* at one time per DMA channel. So the maximum amount of mapped
		* memory would be 255 * 4 channels * 4096 Bytes which is less
		* than 2GB, the limit of a x8 Non-HWWD PCIe slot. This way the
		* pci_map_page function should never fail because of a
		* lack of mappable memory.
		* The function pci_map_page is placed here because we
		* can only, by design, issue up to 255 commands to the
		* hardware at one time per DMA channel. So the maximum
		* amount of mapped memory would be 255 * 4 channels *
		* 4096 Bytes which is less than 2GB, the limit of a x8
		* Non-HWWD PCIe slot. This way the pci_map_page
		* function should never fail because of a lack of
		* mappable memory.
		*/
		dma->dma_addr = pci_map_page(ctrl->card->dev, dma->page,
		dma->pg_off, dma->sub_page.cnt << 9, dir);
		@@ -455,6 +457,7 @@ static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
		rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
		continue;
		}
		}

		set_tracker_dma(ctrl->trackers, tag, dma);
		hw_cmd_buf[ctrl->cmd.idx].command = dma->cmd;

+1 −1