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From 3c40eb8145325b0f5b93b8a169146078cb2c49d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Hundeb=C3=B8ll?= <martin@geanix.com>
Date: Wed, 7 Jun 2023 10:27:12 +0200
Subject: [PATCH] mmc: meson-gx: remove redundant mmc_request_done() call from irq context
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Git-commit: 3c40eb8145325b0f5b93b8a169146078cb2c49d6
Patch-mainline: v6.4
References: git-fixes

The call to mmc_request_done() can schedule, so it must not be called
from irq context. Wake the irq thread if it needs to be called, and let
its existing logic do its work.

Fixes the following kernel bug, which appears when running an RT patched
kernel on the AmLogic Meson AXG A113X SoC:
[   11.111407] BUG: scheduling while atomic: kworker/0:1H/75/0x00010001
[   11.111438] Modules linked in:
[   11.111451] CPU: 0 PID: 75 Comm: kworker/0:1H Not tainted 6.4.0-rc3-rt2-rtx-00081-gfd07f41ed6b4-dirty #1
[   11.111461] Hardware name: RTX AXG A113X Linux Platform Board (DT)
[   11.111469] Workqueue: kblockd blk_mq_run_work_fn
[   11.111492] Call trace:
[   11.111497]  dump_backtrace+0xac/0xe8
[   11.111510]  show_stack+0x18/0x28
[   11.111518]  dump_stack_lvl+0x48/0x60
[   11.111530]  dump_stack+0x18/0x24
[   11.111537]  __schedule_bug+0x4c/0x68
[   11.111548]  __schedule+0x80/0x574
[   11.111558]  schedule_loop+0x2c/0x50
[   11.111567]  schedule_rtlock+0x14/0x20
[   11.111576]  rtlock_slowlock_locked+0x468/0x730
[   11.111587]  rt_spin_lock+0x40/0x64
[   11.111596]  __wake_up_common_lock+0x5c/0xc4
[   11.111610]  __wake_up+0x18/0x24
[   11.111620]  mmc_blk_mq_req_done+0x68/0x138
[   11.111633]  mmc_request_done+0x104/0x118
[   11.111644]  meson_mmc_request_done+0x38/0x48
[   11.111654]  meson_mmc_irq+0x128/0x1f0
[   11.111663]  __handle_irq_event_percpu+0x70/0x114
[   11.111674]  handle_irq_event_percpu+0x18/0x4c
[   11.111683]  handle_irq_event+0x80/0xb8
[   11.111691]  handle_fasteoi_irq+0xa4/0x120
[   11.111704]  handle_irq_desc+0x20/0x38
[   11.111712]  generic_handle_domain_irq+0x1c/0x28
[   11.111721]  gic_handle_irq+0x8c/0xa8
[   11.111735]  call_on_irq_stack+0x24/0x4c
[   11.111746]  do_interrupt_handler+0x88/0x94
[   11.111757]  el1_interrupt+0x34/0x64
[   11.111769]  el1h_64_irq_handler+0x18/0x24
[   11.111779]  el1h_64_irq+0x64/0x68
[   11.111786]  __add_wait_queue+0x0/0x4c
[   11.111795]  mmc_blk_rw_wait+0x84/0x118
[   11.111804]  mmc_blk_mq_issue_rq+0x5c4/0x654
[   11.111814]  mmc_mq_queue_rq+0x194/0x214
[   11.111822]  blk_mq_dispatch_rq_list+0x3ac/0x528
[   11.111834]  __blk_mq_sched_dispatch_requests+0x340/0x4d0
[   11.111847]  blk_mq_sched_dispatch_requests+0x38/0x70
[   11.111858]  blk_mq_run_work_fn+0x3c/0x70
[   11.111865]  process_one_work+0x17c/0x1f0
[   11.111876]  worker_thread+0x1d4/0x26c
[   11.111885]  kthread+0xe4/0xf4
[   11.111894]  ret_from_fork+0x10/0x20

Fixes: 51c5d8447bd7 ("MMC: meson: initial support for GX platforms")
Cc: stable@vger.kernel.org
Signed-off-by: Martin Hundebøll <martin@geanix.com>
Link: https://lore.kernel.org/r/20230607082713.517157-1-martin@geanix.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/mmc/host/meson-gx-mmc.c |   10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -981,11 +981,8 @@ static irqreturn_t meson_mmc_irq(int irq
 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
 		if (data && !cmd->error)
 			data->bytes_xfered = data->blksz * data->blocks;
-		if (meson_mmc_bounce_buf_read(data) ||
-		    meson_mmc_get_next_command(cmd))
-			ret = IRQ_WAKE_THREAD;
-		else
-			ret = IRQ_HANDLED;
+
+		return IRQ_WAKE_THREAD;
 	}
 
 out:
@@ -997,9 +994,6 @@ out:
 		writel(start, host->regs + SD_EMMC_START);
 	}
 
-	if (ret == IRQ_HANDLED)
-		meson_mmc_request_done(host->mmc, cmd->mrq);
-
 	return ret;
 }