On 2022-06-15 13:11, Frank Wunderlich wrote:
Hi,
i have upported a wifi-driver (mt6625l for armhf) for some time and fall now
(at least 5.18) in the
"rejecting DMA map of vmalloc memory" error [1].
maybe anybody here can guide me on how to nail it down and maybe fix it.
as far as i have debugged it, it uses dma_map_single [2] to get dma memory from
a previous
allocated memory region.
this function "kalDevPortRead" in [2] is used via macro HAL_PORT_RD [3] (used
in HAL_READ_RX_PORT
and HAL_READ_INTR_STATUS in same hal.h file)
HAL_READ_INTR_STATUS is always called with an empty int array as buf which i
guess is not the problem.
I think the issue is using the use with an preallocated prSDIOCtrl struct (have
not completely traced
it back where it is allocated).
Put simply, if you want to call dma_map_single() on a buffer, then that
buffer needs to be allocated with kmalloc() (or technically
alloc_pages(), but then dma_map_page() would make more sense when
dealing with entire pages.
Robin.
calls of HAL_PORT_RD/HAL_READ_RX_PORT are in nic{,_rx}.c (with sdio-struct)
([4] as example)
maybe there is a simple way to get an address in preallocated memory as
replacement for the dma_map_simple call (and the unmap of course).
regards Frank
[1]
https://elixir.bootlin.com/linux/latest/source/include/linux/dma-mapping.h#L327
[2]
https://github.com/frank-w/BPI-R2-4.14/blob/5.18-main/drivers/misc/mediatek/connectivity/wlan/gen2/os/linux/hif/ahb/ahb.c#L940
[3]
https://github.com/frank-w/BPI-R2-4.14/blob/5.18-main/drivers/misc/mediatek/connectivity/wlan/gen2/include/nic/hal.h#L176
[4]
https://github.com/frank-w/BPI-R2-4.14/blob/5.18-main/drivers/misc/mediatek/connectivity/wlan/gen2/nic/nic_rx.c#L3604
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