Re: [PATCH 1/1] scsi/ufshcd: Fix NULL pointer dereference for in ufshcd_init

From: Evan Green
Date: Tue Aug 28 2018 - 15:42:21 EST

On Tue, Aug 7, 2018 at 10:48 AM Vivek Gautam
<vivek.gautam@xxxxxxxxxxxxxx> wrote:
> Error paths in ufshcd_init() ufshcd_hba_exit() killed clk_scaling
> workqueue when the workqueue is actually created quite late in
> ufshcd_init().
> So, we end up getting NULL pointer dereference in such error paths.
> Fix this by moving clk_scaling initialization and kill codes to
> two separate methods, and call them at required places.
> Fixes: 401f1e4490ee ("scsi: ufs: don't suspend clock scaling during clock
> gating")
> Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
> Cc: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> Cc: Evan Green <evgreen@xxxxxxxxxxxx>
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> ---
> Bjorn, Subhash,
> I am not certain of some of these devfreq, and clk_scaling bits
> that are moved as part of this patch. Please help in reviewing the
> change in the light of these features, and related sequence should
> be followed.
> Thanks.

You're right, there is a lot of logic moving around here. I think this
looks okay to me.

Reviewed-by: Evan Green <evgreen@xxxxxxxxxxxx>