mmc: jz4740: Apply DMA engine limits to maximum segment size
authorAidan MacDonald <aidanmacdonald.0x0@gmail.com>
Mon, 11 Apr 2022 15:37:53 +0000 (16:37 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 9 Jun 2022 08:22:33 +0000 (10:22 +0200)
commit353298cadbd4c7d8e8a16d6000066414694933c3
treee5f3a890d8c79dc2b357c8ccfdae24fd66d7692f
parent27f672af28a8e9b783ff7f0eaf7ef2fbd5a2f4ba
mmc: jz4740: Apply DMA engine limits to maximum segment size

[ Upstream commit afadb04f1d6e74b18a253403f5274cde5e3fd7bd ]

Do what is done in other DMA-enabled MMC host drivers (cf. host/mmci.c) and
limit the maximum segment size based on the DMA engine's capabilities. This
is needed to avoid warnings like the following with CONFIG_DMA_API_DEBUG=y.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 21 at kernel/dma/debug.c:1162 debug_dma_map_sg+0x2f4/0x39c
DMA-API: jz4780-dma 13420000.dma-controller: mapping sg segment longer than device claims to support [len=98304] [max=65536]
CPU: 0 PID: 21 Comm: kworker/0:1H Not tainted 5.18.0-rc1 #19
Workqueue: kblockd blk_mq_run_work_fn
Stack : 81575aec 00000004 80620000 80620000 80620000 805e7358 00000009 801537ac
        814c832c 806276e3 806e34b4 80620000 81575aec 00000001 81575ab8 09291444
        00000000 00000000 805e7358 81575958 ffffffea 8157596c 00000000 636f6c62
        6220646b 80387a70 0000000f 6d5f6b6c 80620000 00000000 81575ba4 00000009
        805e170c 80896640 00000001 00010000 00000000 00000000 00006098 806e0000
        ...
Call Trace:
[<80107670>] show_stack+0x84/0x120
[<80528cd8>] __warn+0xb8/0xec
[<80528d78>] warn_slowpath_fmt+0x6c/0xb8
[<8016f1d4>] debug_dma_map_sg+0x2f4/0x39c
[<80169d4c>] __dma_map_sg_attrs+0xf0/0x118
[<8016a27c>] dma_map_sg_attrs+0x14/0x28
[<804f66b4>] jz4740_mmc_prepare_dma_data+0x74/0xa4
[<804f6714>] jz4740_mmc_pre_request+0x30/0x54
[<804f4ff4>] mmc_blk_mq_issue_rq+0x6e0/0x7bc
[<804f5590>] mmc_mq_queue_rq+0x220/0x2d4
[<8038b2c0>] blk_mq_dispatch_rq_list+0x480/0x664
[<80391040>] blk_mq_do_dispatch_sched+0x2dc/0x370
[<80391468>] __blk_mq_sched_dispatch_requests+0xec/0x164
[<80391540>] blk_mq_sched_dispatch_requests+0x44/0x94
[<80387900>] __blk_mq_run_hw_queue+0xb0/0xcc
[<80134c14>] process_one_work+0x1b8/0x264
[<80134ff8>] worker_thread+0x2ec/0x3b8
[<8013b13c>] kthread+0x104/0x10c
[<80101dcc>] ret_from_kernel_thread+0x14/0x1c

---[ end trace 0000000000000000 ]---

Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Link: https://lore.kernel.org/r/20220411153753.50443-1-aidanmacdonald.0x0@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/mmc/host/jz4740_mmc.c