lantiq: 4.19: fix panic when using the DMA API

With kernel 4.19 the DMA API relies on a struct device to work properly.
Backport upstream patches which passed a struct device instead of NULL
to the DMA API.

Fixes kernel panics during boot.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Mathias Kresin <dev@kresin.me>

1 files changed, 50 insertions, 0 deletions

diff --git a/target/linux/lantiq/patches-4.19/0006-MIPS-lantiq-pass-struct-device-to-DMA-API-functions.patch b/target/linux/lantiq/patches-4.19/0006-MIPS-lantiq-pass-struct-device-to-DMA-API-functions.patch
new file mode 100644
index 0000000000..412dd62050
--- /dev/null
+++ b/target/linux/lantiq/patches-4.19/0006-MIPS-lantiq-pass-struct-device-to-DMA-API-functions.patch
@@ -0,0 +1,50 @@
+From 74f03104ed465ff71b11076ef620e4eaa53dbf74 Mon Sep 17 00:00:00 2001
+From: Christoph Hellwig <hch@lst.de>
+Date: Fri, 1 Feb 2019 09:47:44 +0100
+Subject: [PATCH] MIPS: lantiq: pass struct device to DMA API functions
+
+The DMA API generally relies on a struct device to work properly, and
+only barely works without one for legacy reasons.  Pass the easily
+available struct device from the platform_device to remedy this.
+
+Also use GFP_KERNEL instead of GFP_ATOMIC as the gfp_t for the memory
+allocation, as we aren't in interrupt context or under a lock.
+
+Note that this whole function looks somewhat bogus given that we never
+even look at the returned dma address, and the CPHYSADDR magic on
+a returned noncached mapping looks "interesting".  But I'll leave
+that to people more familiar with the code to sort out.
+
+Signed-off-by: Christoph Hellwig <hch@lst.de>
+Signed-off-by: Paul Burton <paul.burton@mips.com>
+Cc: John Crispin <john@phrozen.org>
+Cc: Vinod Koul <vkoul@kernel.org>
+Cc: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
+Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
+Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
+Cc: Felipe Balbi <balbi@kernel.org>
+Cc: linux-mips@vger.kernel.org
+Cc: linux-kernel@vger.kernel.org
+Cc: dmaengine@vger.kernel.org
+Cc: netdev@vger.kernel.org
+Cc: linux-usb@vger.kernel.org
+Cc: linux-fbdev@vger.kernel.org
+Cc: alsa-devel@alsa-project.org
+Cc: iommu@lists.linux-foundation.org
+---
+ arch/mips/lantiq/xway/vmmc.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/arch/mips/lantiq/xway/vmmc.c
++++ b/arch/mips/lantiq/xway/vmmc.c
+@@ -31,8 +31,8 @@ static int vmmc_probe(struct platform_de
+ 	dma_addr_t dma;
+ 
+ 	cp1_base =
+-		(void *) CPHYSADDR(dma_alloc_coherent(NULL, CP1_SIZE,
+-						    &dma, GFP_ATOMIC));
++		(void *) CPHYSADDR(dma_alloc_coherent(&pdev->dev, CP1_SIZE,
++						    &dma, GFP_KERNEL));
+ 
+ 	gpio_count = of_gpio_count(pdev->dev.of_node);
+ 	while (gpio_count > 0) {