On 06/01/2022 17:44, Greg KH wrote:
On Thu, Jan 06, 2022 at 05:24:27PM +0000, Bryan O'Donoghue wrote:
On 03/01/2022 05:51, Manivannan Sadhasivam wrote:
On Mon, Jan 03, 2022 at 03:03:15AM +0000, Bryan O'Donoghue wrote:
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@xxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Can you please CC stable list for backporting?
Thanks,
Mani
NP.
+ cc stable
FWIW I believe Greg's scripts will pick up on Fixes: tags automatically
No, that is NOT the way to ensure that a patch will get picked up, that
is a "this might eventually get there".
Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.
thanks,
greg k-h
Good to know
I've just been using Fixes: for the most part
Thanks
---
bod
