Re: [PATCH] spi: spi-cadence-quadspi: Fix division by zero warning

[池田 義隆 <ikeda@xxxxxxxxxxxx>]

On 2021/07/13 21:25, Mark Brown wrote:
> On Tue, Jul 13, 2021 at 07:23:12AM +0000, Yoshitaka Ikeda wrote:
>> Fix below division by zero warning:
>> - Added an if statement because buswidth can be zero, resulting in division by zero.
>> - The modified code was based on another driver (atmel-quadspi).
>>
>> [    0.795337] Division by zero in kernel.
>> [    0.797878] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.12.0-xxx-xxxx+ #1
>> [    0.803782] Hardware name: Altera SOCFPGA
>> [    0.806481] Backtrace:
>> [    0.807628] [<807fd2b0>] (dump_backtrace) from [<807fd554>] (show_stack+0x20/0x24)
> 
> Please think hard before including complete backtraces in upstream
> reports, they are very large and contain almost no useful information
> relative to their size so often obscure the relevant content in your
> message. If part of the backtrace is usefully illustrative (it often is
> for search engines if nothing else) then it's usually better to pull out
> the relevant sections.

Thanks for the reply.

Indeed, I too think that the tracing part should be limited to the useful range.
I would like to modify the tracing part as follows and repost it.
Do you think I should narrow it down further or do you think it is too narrow? Or unnecessary?

[    0.795337] Division by zero in kernel.
  :
[    0.834051] [<807fd40c>] (__div0) from [<804e1acc>] (Ldiv0+0x8/0x10)
[    0.839097] [<805f0710>] (cqspi_exec_mem_op) from [<805edb4c>] (spi_mem_exec_op+0x3b0/0x3f8)