On Fri, Jul 02, 2021 at 12:39:41PM +0100, Robin Murphy wrote: > On 2021-07-02 04:08, Guenter Roeck wrote: > > On Thu, Jun 24, 2021 at 11:55:26PM +0800, Claire Chang wrote: > > > If a device is not behind an IOMMU, we look up the device node and set > > > up the restricted DMA when the restricted-dma-pool is presented. > > > > > > Signed-off-by: Claire Chang <tientzu@xxxxxxxxxxxx> > > > Tested-by: Stefano Stabellini <sstabellini@xxxxxxxxxx> > > > Tested-by: Will Deacon <will@xxxxxxxxxx> > > > > With this patch in place, all sparc and sparc64 qemu emulations > > fail to boot. Symptom is that the root file system is not found. > > Reverting this patch fixes the problem. Bisect log is attached. > > Ah, OF_ADDRESS depends on !SPARC, so of_dma_configure_id() is presumably > returning an unexpected -ENODEV from the of_dma_set_restricted_buffer() > stub. That should probably be returning 0 instead, since either way it's not > an error condition for it to simply do nothing. Something like below? Will --->8 >From 4d9dcb9210c1f37435b6088284e04b6b36ee8c4d Mon Sep 17 00:00:00 2001 From: Will Deacon <will@xxxxxxxxxx> Date: Fri, 2 Jul 2021 14:13:28 +0100 Subject: [PATCH] of: Return success from of_dma_set_restricted_buffer() when !OF_ADDRESS When CONFIG_OF_ADDRESS=n, of_dma_set_restricted_buffer() returns -ENODEV and breaks the boot for sparc[64] machines. Return 0 instead, since the function is essentially a glorified NOP in this configuration. Cc: Claire Chang <tientzu@xxxxxxxxxxxx> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> Suggested-by: Robin Murphy <robin.murphy@xxxxxxx> Link: https://lore.kernel.org/r/20210702030807.GA2685166@xxxxxxxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> --- drivers/of/of_private.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index 8fde97565d11..34dd548c5eac 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -173,7 +173,8 @@ static inline int of_dma_get_range(struct device_node *np, static inline int of_dma_set_restricted_buffer(struct device *dev, struct device_node *np) { - return -ENODEV; + /* Do nothing, successfully. */ + return 0; } #endif -- 2.32.0.93.g670b81a890-goog
