On Tue, May 28, 2019 at 03:33:09PM +0300, Kalle Valo wrote:

Yeah, I don't see how that thread proves that these patches are correct.

Sure, I didn't mean that we came to an agreement that these patches are
correct.

quoted

Further, I e-mailed Greg K-H about when should we use devm_kmalloc().

On Tue, May 28, 2019 at 08:32:57AM +0800, Gen Zhang wrote:

quoted

devm_kmalloc() is used to allocate memory for a driver dev. Comments
above the definition and doc 
(https://www.kernel.org/doc/Documentation/driver-model/devres.txt) all
imply that allocated the memory is automatically freed on driver attach,
no matter allocation fail or not. However, I examined the code, and
there are many sites that devm_kfree() is used to free devm_kmalloc().
e.g. hisi_sas_debugfs_init() in drivers/scsi/hisi_sas/hisi_sas_main.c.
So I am totally confused about this issue. Can anybody give me some
guidance? When should we use devm_kfree()?

He replied: If you "know" you need to free the memory now, 
call devm_kfree(). If you want to wait for it to be cleaned up latter, 
like normal, then do not call it.

So could please look in to this issue?

Sorry, no time to investigate this in detail. If you think the patches
are correct you can resend them and get someone familiar with the driver
to provide Reviewed-by, then I will apply them.

-- 
Kalle Valo

Ok, thanks for your time. I will follow your suggestions.

Thanks
Gen