soundwire: Revert "soundwire: qcom: Add set_channel_map api support"

In the Linux kernel, the following vulnerability has been resolved:

soundwire: Revert "soundwire: qcom: Add set_channel_map api support"

This reverts commit 7796c97df6b1b2206681a07f3c80f6023a6593d5.

This patch broke Dragonboard 845c (sdm845). I see:

Unexpected kernel BRK exception at EL1

Internal error: BRK handler: 00000000f20003e8 [#1] SMP

pc : qcom_swrm_set_channel_map+0x7c/0x80 [soundwire_qcom]

lr : snd_soc_dai_set_channel_map+0x34/0x78

Call trace:

qcom_swrm_set_channel_map+0x7c/0x80 [soundwire_qcom] (P)

sdm845_dai_init+0x18c/0x2e0 [snd_soc_sdm845]

snd_soc_link_init+0x28/0x6c

snd_soc_bind_card+0x5f4/0xb0c

snd_soc_register_card+0x148/0x1a4

devm_snd_soc_register_card+0x50/0xb0

sdm845_snd_platform_probe+0x124/0x148 [snd_soc_sdm845]

platform_probe+0x6c/0xd0

really_probe+0xc0/0x2a4

__driver_probe_device+0x7c/0x130

driver_probe_device+0x40/0x118

__device_attach_driver+0xc4/0x108

bus_for_each_drv+0x8c/0xf0

__device_attach+0xa4/0x198

device_initial_probe+0x18/0x28

bus_probe_device+0xb8/0xbc

deferred_probe_work_func+0xac/0xfc

process_one_work+0x244/0x658

worker_thread+0x1b4/0x360

kthread+0x148/0x228

ret_from_fork+0x10/0x20

Kernel panic - not syncing: BRK handler: Fatal exception

Dan has also reported following issues with the original patch

https://lore.kernel.org/all/[email protected]/

Bug #1:

The zeroeth element of ctrl->pconfig[] is supposed to be unused. We

start counting at 1. However this code sets ctrl->pconfig[0].ch_mask = 128.

Bug #2:

There are SLIM_MAX_TX_PORTS (16) elements in tx_ch[] array but only

QCOM_SDW_MAX_PORTS + 1 (15) in the ctrl->pconfig[] array so it corrupts

memory like Yongqin Liu pointed out.

Bug 3:

Like Jie Gan pointed out, it erases all the tx information with the rx

information.