Hi Grygorii, Thanks for the report. On 27/07/18 00:45, Grygorii Strashko wrote: [...]
With this series applied I can't boot TI ARM32 am574x-idk any more. And log output is full of "DMA mask not set" -
That's somewhat expected - as the relevant commit message mentions, there will be bugs flushed out by this change, but the point is to fix them :)
nobody sets dma_mask for platform bus in case of OF boot :(
Right, after a brief investigation, that one turns out to be nice and straightforward to explain and fix; I'll write up the patch shortly.
[...]
[ 3.793493] ti-qspi 4b300000.qspi: dma_alloc_coherent failed, using PIO mode [ 3.801088] Unable to handle kernel NULL pointer dereference at virtual address 00000080
[...]
[ 4.602777] [<c04d87a4>] (omap_dma_write) from [<c04d8dc0>] (omap_dma_start_desc+0x78/0x150) [ 4.611258] [<c04d8d48>] (omap_dma_start_desc) from [<c04d9028>] (omap_dma_issue_pending+0x90/0x98) [ 4.620347] r9:ed002780 r8:00000000 r7:00000010 r6:ee2bdd00 r5:ee2bdd4c r4:ee2bdd00 [ 4.628130] [<c04d8f98>] (omap_dma_issue_pending) from [<c0608d1c>] (ti_qspi_dma_xfer+0x8c/0x13c) [ 4.637039] r5:00000000 r4:ee7e1b28 [ 4.640636] [<c0608c90>] (ti_qspi_dma_xfer) from [<c06090b0>] (ti_qspi_exec_mem_op+0x2e4/0x32c)
Hooray, a real bug! Since dma_alloc_coherent() could have failed due to lack of memory or any other reason, that's not even directly related to this change, we've simply helped uncover it. I guess that PIO fallback path hasn't been tested recently, because it clearly doesn't work. It would be good if someone who knows the ti-qspi driver and has the means to test it could figure that one out before also adding the missing dma_set_coherent_mask() call.
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