This is a note to let you know that I've just added the patch titled mmc: meson-gx: remove redundant mmc_request_done() call from irq context to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-meson-gx-remove-redundant-mmc_request_done-call-from-irq-context.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 3c40eb8145325b0f5b93b8a169146078cb2c49d6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Hundeb=C3=B8ll?= <martin@xxxxxxxxxx> Date: Wed, 7 Jun 2023 10:27:12 +0200 Subject: mmc: meson-gx: remove redundant mmc_request_done() call from irq context MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Martin Hundebøll <martin@xxxxxxxxxx> commit 3c40eb8145325b0f5b93b8a169146078cb2c49d6 upstream. 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@xxxxxxxxxxxxxxx Signed-off-by: Martin Hundebøll <martin@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230607082713.517157-1-martin@xxxxxxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -973,11 +973,8 @@ 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: @@ -989,9 +986,6 @@ out: writel(start, host->regs + SD_EMMC_START); } - if (ret == IRQ_HANDLED) - meson_mmc_request_done(host->mmc, cmd->mrq); - return ret; } Patches currently in stable-queue which might be from martin@xxxxxxxxxx are queue-5.4/mmc-meson-gx-remove-redundant-mmc_request_done-call-from-irq-context.patch