4.20-stable review patch. If anyone has any objections, please let me know.
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From: Rafał Miłecki rafal@milecki.pl
commit 321c46b91550adc03054125fa7a1639390608e1a upstream.
So far we never had any device registered for the SoC. This resulted in some small issues that we kept ignoring like: 1) Not working GPIOLIB_IRQCHIP (gpiochip_irqchip_add_key() failing) 2) Lack of proper tree in the /sys/devices/ 3) mips_dma_alloc_coherent() silently handling empty coherent_dma_mask
Kernel 4.19 came with a lot of DMA changes and caused a regression on bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms") DMA coherent allocations just fail. Example: [ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed [ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA [ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12 [ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded
The bgmac driver also triggers a WARNING: [ 0.959486] ------------[ cut here ]------------ [ 0.964387] WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 bgmac_enet_probe+0x1b4/0x5c4 [ 0.973751] Modules linked in: [ 0.976913] CPU: 0 PID: 1 Comm: swapper Not tainted 4.19.9 #0 [ 0.982750] Stack : 804a0000 804597c4 00000000 00000000 80458fd8 8381bc2c 838282d4 80481a47 [ 0.991367] 8042e3ec 00000001 804d38f0 00000204 83980000 00000065 8381bbe0 6f55b24f [ 0.999975] 00000000 00000000 80520000 00002018 00000000 00000075 00000007 00000000 [ 1.008583] 00000000 80480000 000ee811 00000000 00000000 00000000 80432c00 80248db8 [ 1.017196] 00000009 00000204 83980000 803ad7b0 00000000 801feeec 00000000 804d0000 [ 1.025804] ... [ 1.028325] Call Trace: [ 1.030875] [<8000aef8>] show_stack+0x58/0x100 [ 1.035513] [<8001f8b4>] __warn+0xe4/0x118 [ 1.039708] [<8001f9a4>] warn_slowpath_null+0x48/0x64 [ 1.044935] [<80248db8>] bgmac_enet_probe+0x1b4/0x5c4 [ 1.050101] [<802498e0>] bgmac_probe+0x558/0x590 [ 1.054906] [<80252fd0>] bcma_device_probe+0x38/0x70 [ 1.060017] [<8020e1e8>] really_probe+0x170/0x2e8 [ 1.064891] [<8020e714>] __driver_attach+0xa4/0xec [ 1.069784] [<8020c1e0>] bus_for_each_dev+0x58/0xb0 [ 1.074833] [<8020d590>] bus_add_driver+0xf8/0x218 [ 1.079731] [<8020ef24>] driver_register+0xcc/0x11c [ 1.084804] [<804b54cc>] bgmac_init+0x1c/0x44 [ 1.089258] [<8000121c>] do_one_initcall+0x7c/0x1a0 [ 1.094343] [<804a1d34>] kernel_init_freeable+0x150/0x218 [ 1.099886] [<803a082c>] kernel_init+0x10/0x104 [ 1.104583] [<80005878>] ret_from_kernel_thread+0x14/0x1c [ 1.110107] ---[ end trace f441c0d873d1fb5b ]---
This patch setups a "struct device" (and passes it to the bcma) which allows fixing all the mentioned problems. It'll also require a tiny bcma patch which will follow through the wireless tree & its maintainer.
Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms") Signed-off-by: Rafał Miłecki rafal@milecki.pl Signed-off-by: Paul Burton paul.burton@mips.com Acked-by: Hauke Mehrtens hauke@hauke-m.de Cc: Christoph Hellwig hch@lst.de Cc: Linus Walleij linus.walleij@linaro.org Cc: linux-wireless@vger.kernel.org Cc: Ralf Baechle ralf@linux-mips.org Cc: James Hogan jhogan@kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/mips/bcm47xx/setup.c | 31 +++++++++++++++++++++++++++++++ include/linux/bcma/bcma_soc.h | 1 + 2 files changed, 32 insertions(+)
--- a/arch/mips/bcm47xx/setup.c +++ b/arch/mips/bcm47xx/setup.c @@ -173,6 +173,31 @@ void __init plat_mem_setup(void) pm_power_off = bcm47xx_machine_halt; }
+#ifdef CONFIG_BCM47XX_BCMA +static struct device * __init bcm47xx_setup_device(void) +{ + struct device *dev; + int err; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return NULL; + + err = dev_set_name(dev, "bcm47xx_soc"); + if (err) { + pr_err("Failed to set SoC device name: %d\n", err); + kfree(dev); + return NULL; + } + + err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); + if (err) + pr_err("Failed to set SoC DMA mask: %d\n", err); + + return dev; +} +#endif + /* * This finishes bus initialization doing things that were not possible without * kmalloc. Make sure to call it late enough (after mm_init). @@ -183,6 +208,10 @@ void __init bcm47xx_bus_setup(void) if (bcm47xx_bus_type == BCM47XX_BUS_TYPE_BCMA) { int err;
+ bcm47xx_bus.bcma.dev = bcm47xx_setup_device(); + if (!bcm47xx_bus.bcma.dev) + panic("Failed to setup SoC device\n"); + err = bcma_host_soc_init(&bcm47xx_bus.bcma); if (err) panic("Failed to initialize BCMA bus (err %d)", err); @@ -235,6 +264,8 @@ static int __init bcm47xx_register_bus_c #endif #ifdef CONFIG_BCM47XX_BCMA case BCM47XX_BUS_TYPE_BCMA: + if (device_register(bcm47xx_bus.bcma.dev)) + pr_err("Failed to register SoC device\n"); bcma_bus_register(&bcm47xx_bus.bcma.bus); break; #endif --- a/include/linux/bcma/bcma_soc.h +++ b/include/linux/bcma/bcma_soc.h @@ -6,6 +6,7 @@
struct bcma_soc { struct bcma_bus bus; + struct device *dev; };
int __init bcma_host_soc_register(struct bcma_soc *soc);