From: Bryan O'Donoghue bryan.odonoghue@linaro.org
commit 5c23b3f965bc9ee696bf2ed4bdc54d339dd9a455 upstream.
Interacting with a NAND chip on an IPQ6018 I found that the qcomsmem NAND partition parser was returning -EPROBE_DEFER waiting for the main smem driver to load.
This caused the board to reset. Playing about with the probe() function shows that the problem lies in the core clock being switched off before the nandc_unalloc() routine has completed.
If we look at how qcom_nandc_remove() tears down allocated resources we see the expected order is
qcom_nandc_unalloc(nandc);
clk_disable_unprepare(nandc->aon_clk); clk_disable_unprepare(nandc->core_clk);
dma_unmap_resource(&pdev->dev, nandc->base_dma, resource_size(res), DMA_BIDIRECTIONAL, 0);
Tweaking probe() to both bring up and tear-down in that order removes the reset if we end up deferring elsewhere.
Fixes: c76b78d8ec05 ("mtd: nand: Qualcomm NAND controller driver") Signed-off-by: Bryan O'Donoghue bryan.odonoghue@linaro.org Reviewed-by: Manivannan Sadhasivam mani@kernel.org Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Link: https://lore.kernel.org/linux-mtd/20220103030316.58301-2-bryan.odonoghue@lin... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mtd/nand/raw/qcom_nandc.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-)
--- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -2,7 +2,6 @@ /* * Copyright (c) 2016, The Linux Foundation. All rights reserved. */ - #include <linux/clk.h> #include <linux/slab.h> #include <linux/bitops.h> @@ -2968,10 +2967,6 @@ static int qcom_nandc_probe(struct platf if (!nandc->base_dma) return -ENXIO;
- ret = qcom_nandc_alloc(nandc); - if (ret) - goto err_nandc_alloc; - ret = clk_prepare_enable(nandc->core_clk); if (ret) goto err_core_clk; @@ -2980,6 +2975,10 @@ static int qcom_nandc_probe(struct platf if (ret) goto err_aon_clk;
+ ret = qcom_nandc_alloc(nandc); + if (ret) + goto err_nandc_alloc; + ret = qcom_nandc_setup(nandc); if (ret) goto err_setup; @@ -2991,15 +2990,14 @@ static int qcom_nandc_probe(struct platf return 0;
err_setup: + qcom_nandc_unalloc(nandc); +err_nandc_alloc: clk_disable_unprepare(nandc->aon_clk); err_aon_clk: clk_disable_unprepare(nandc->core_clk); err_core_clk: - qcom_nandc_unalloc(nandc); -err_nandc_alloc: dma_unmap_resource(dev, res->start, resource_size(res), DMA_BIDIRECTIONAL, 0); - return ret; }