[PATCH v1] mmc: mtk-sd: Use readl_poll_timeout_atomic in msdc_reset_hw

From: Pablo Sun
Date: Fri Sep 22 2023 - 05:54:48 EST


Use atomic readl_poll_timeout_atomic, because msdc_reset_hw
may be invoked in IRQ handler in the following context:

msdc_irq() -> msdc_cmd_done() -> msdc_reset_hw()

The following kernel BUG stack trace can be observed on
Genio 1200 EVK after initializing MSDC1 hardware during kernel boot:

[ 1.187441] BUG: scheduling while atomic: swapper/0/0/0x00010002
[ 1.189157] Modules linked in:
[ 1.204633] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.15.42-mtk+modified #1
[ 1.205713] Hardware name: MediaTek Genio 1200 EVK-P1V2-EMMC (DT)
[ 1.206484] Call trace:
[ 1.206796] dump_backtrace+0x0/0x1ac
[ 1.207266] show_stack+0x24/0x30
[ 1.207692] dump_stack_lvl+0x68/0x84
[ 1.208162] dump_stack+0x1c/0x38
[ 1.208587] __schedule_bug+0x68/0x80
[ 1.209056] __schedule+0x6ec/0x7c0
[ 1.209502] schedule+0x7c/0x110
[ 1.209915] schedule_hrtimeout_range_clock+0xc4/0x1f0
[ 1.210569] schedule_hrtimeout_range+0x20/0x30
[ 1.211148] usleep_range_state+0x84/0xc0
[ 1.211661] msdc_reset_hw+0xc8/0x1b0
[ 1.212134] msdc_cmd_done.isra.0+0x4ac/0x5f0
[ 1.212693] msdc_irq+0x104/0x2d4
[ 1.213121] __handle_irq_event_percpu+0x68/0x280
[ 1.213725] handle_irq_event+0x70/0x15c
[ 1.214230] handle_fasteoi_irq+0xb0/0x1a4
[ 1.214755] handle_domain_irq+0x6c/0x9c
[ 1.215260] gic_handle_irq+0xc4/0x180
[ 1.215741] call_on_irq_stack+0x2c/0x54
[ 1.216245] do_interrupt_handler+0x5c/0x70
[ 1.216782] el1_interrupt+0x30/0x80
[ 1.217242] el1h_64_irq_handler+0x1c/0x2c
[ 1.217769] el1h_64_irq+0x78/0x7c
[ 1.218206] cpuidle_enter_state+0xc8/0x600
[ 1.218744] cpuidle_enter+0x44/0x5c
[ 1.219205] do_idle+0x224/0x2d0
[ 1.219624] cpu_startup_entry+0x30/0x80
[ 1.220129] rest_init+0x108/0x134
[ 1.220568] arch_call_rest_init+0x1c/0x28
[ 1.221094] start_kernel+0x6c0/0x700
[ 1.221564] __primary_switched+0xc0/0xc8

Fixes: ffaea6ebfe9c ("mmc: mtk-sd: Use readl_poll_timeout instead of open-coded polling")
Signed-off-by: Pablo Sun <pablo.sun@xxxxxxxxxxxx>
---
drivers/mmc/host/mtk-sd.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 5392200cfdf7..97f7c3d4be6e 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -669,11 +669,11 @@ static void msdc_reset_hw(struct msdc_host *host)
u32 val;

sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_RST);
- readl_poll_timeout(host->base + MSDC_CFG, val, !(val & MSDC_CFG_RST), 0, 0);
+ readl_poll_timeout_atomic(host->base + MSDC_CFG, val, !(val & MSDC_CFG_RST), 0, 0);

sdr_set_bits(host->base + MSDC_FIFOCS, MSDC_FIFOCS_CLR);
- readl_poll_timeout(host->base + MSDC_FIFOCS, val,
- !(val & MSDC_FIFOCS_CLR), 0, 0);
+ readl_poll_timeout_atomic(host->base + MSDC_FIFOCS, val,
+ !(val & MSDC_FIFOCS_CLR), 0, 0);

val = readl(host->base + MSDC_INT);
writel(val, host->base + MSDC_INT);
--
2.18.0