mirror of https://gitee.com/openkylin/linux.git
59f647c25a
The Freescale Elo DMA driver runs an internal self-test before registering the channels with the DMA engine. This self-test has a fundemental flaw in that it calls the DMA engine's callback functions directly before the registration. However, the registration initializes some variables that the callback functions uses, namely the device struct. The code works today because there are two device structs: the one created by the DMA engine, and one created by the Open Firmware (OF) subsystem. The self-test currently uses the device struct created by OF. However, in the future, some of the device structs created by OF will be eliminated. This means that the self-test will only have access to the device struct created by the DMA engine. But this device struct isn't initialized when the self-test runs, and this causes a kernel panic. Since there is already a DMA test module (dmatest), the internal self-test code is not useful anyway. It is extremely unlikely that the test will fail in normal usage. It may have been helpful during development, but not any more. Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Li Yang <leoli@freescale.com> Cc: Scott Wood <scottwood@freescale.com> Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| dmaengine.c | ||
| dmatest.c | ||
| dw_dmac.c | ||
| dw_dmac_regs.h | ||
| fsldma.c | ||
| fsldma.h | ||
| ioat.c | ||
| ioat_dca.c | ||
| ioat_dma.c | ||
| ioatdma.h | ||
| ioatdma_hw.h | ||
| ioatdma_registers.h | ||
| iop-adma.c | ||
| iovlock.c | ||
| mv_xor.c | ||
| mv_xor.h | ||