[PATCH] mtd: rawnand: stm32_fmc2: avoid overlapping mappings on ECC buffer

[Miquel Raynal]

On Tue, 12 Aug 2025 09:26:58 +0200, Christophe Kerello wrote:
> Avoid below overlapping mappings by using a contiguous
> non-cacheable buffer.
> 
> [    4.077708] DMA-API: stm32_fmc2_nfc 48810000.nand-controller: cacheline tracking EEXIST,
> overlapping mappings aren't supported
> [    4.089103] WARNING: CPU: 1 PID: 44 at kernel/dma/debug.c:568 add_dma_entry+0x23c/0x300
> [    4.097071] Modules linked in:
> [    4.100101] CPU: 1 PID: 44 Comm: kworker/u4:2 Not tainted 6.1.82 #1
> [    4.106346] Hardware name: STMicroelectronics STM32MP257F VALID1 SNOR / MB1704 (LPDDR4 Power discrete) + MB1703 + MB1708 (SNOR MB1730) (DT)
> [    4.118824] Workqueue: events_unbound deferred_probe_work_func
> [    4.124674] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [    4.131624] pc : add_dma_entry+0x23c/0x300
> [    4.135658] lr : add_dma_entry+0x23c/0x300
> [    4.139792] sp : ffff800009dbb490
> [    4.143016] x29: ffff800009dbb4a0 x28: 0000000004008022 x27: ffff8000098a6000
> [    4.150174] x26: 0000000000000000 x25: ffff8000099e7000 x24: ffff8000099e7de8
> [    4.157231] x23: 00000000ffffffff x22: 0000000000000000 x21: ffff8000098a6a20
> [    4.164388] x20: ffff000080964180 x19: ffff800009819ba0 x18: 0000000000000006
> [    4.171545] x17: 6361727420656e69 x16: 6c6568636163203a x15: 72656c6c6f72746e
> [    4.178602] x14: 6f632d646e616e2e x13: ffff800009832f58 x12: 00000000000004ec
> [    4.185759] x11: 00000000000001a4 x10: ffff80000988af58 x9 : ffff800009832f58
> [    4.192916] x8 : 00000000ffffefff x7 : ffff80000988af58 x6 : 80000000fffff000
> [    4.199972] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000
> [    4.207128] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000812d2c40
> [    4.214185] Call trace:
> [    4.216605]  add_dma_entry+0x23c/0x300
> [    4.220338]  debug_dma_map_sg+0x198/0x350
> [    4.224373]  __dma_map_sg_attrs+0xa0/0x110
> [    4.228411]  dma_map_sg_attrs+0x10/0x2c
> [    4.232247]  stm32_fmc2_nfc_xfer.isra.0+0x1c8/0x3fc
> [    4.237088]  stm32_fmc2_nfc_seq_read_page+0xc8/0x174
> [    4.242127]  nand_read_oob+0x1d4/0x8e0
> [    4.245861]  mtd_read_oob_std+0x58/0x84
> [    4.249596]  mtd_read_oob+0x90/0x150
> [    4.253231]  mtd_read+0x68/0xac
> 
> [...]

Applied to mtd/fixes, thanks!

[1/1] mtd: rawnand: stm32_fmc2: avoid overlapping mappings on ECC buffer
      commit: 513c40e59d5a414ab763a9c84797534b5e8c208d

Patche(s) should be available on mtd/linux.git and will be
part of the next PR (provided that no robot complains by then).

Kind regards,
Miquèl