Re: [PATCH] staging: irda: resolve sparse errors due to implicit pci_power_t casts

[Matthew Giassa <matthew@giassa.net>]

* Greg KH <gregkh@linuxfoundation.org> [2017-10-18 16:12:16 +0200]:

>On Thu, Oct 05, 2017 at 04:38:23PM -0700, Matthew Giassa wrote:
>> Explicitly casting pci_power_t types to resolve sparse warnings (shown
>> below).
>>
>> Also fixing a related logging bug where pci_power_t is cast to unsigned
>> (can be negative, i.e. PCI_POWER_ERROR).
>>
>> Original sparse report:
>>
>> drivers/staging/irda/drivers//vlsi_ir.c:170:51: warning: cast from
>> restricted pci_power_t
>> drivers/staging/irda/drivers//vlsi_ir.c:1726:39: warning: restricted
>> pci_power_t degrades to integer
>> drivers/staging/irda/drivers//vlsi_ir.c:1728:45: warning: incorrect type
>> in assignment (different base types)
>> drivers/staging/irda/drivers//vlsi_ir.c:1728:45:    expected restricted
>> pci_power_t [usertype] current_state
>> drivers/staging/irda/drivers//vlsi_ir.c:1728:45:    got int [signed]
>> [usertype] event
>> drivers/staging/irda/drivers//vlsi_ir.c:1748:29: warning: incorrect type
>> in assignment (different base types)
>> drivers/staging/irda/drivers//vlsi_ir.c:1748:29:    expected restricted
>> pci_power_t [usertype] current_state
>> drivers/staging/irda/drivers//vlsi_ir.c:1748:29:    got int [signed]
>> [usertype] event
>
>Please do not line-wrap lines like this, it makes them harder to
>understand.
>
Duly noted.

>>
>> Warnings no longer present.
>>
>> Signed-off-by: Matthew Giassa <matthew@giassa.net>
>> ---
>>  drivers/staging/irda/drivers/vlsi_ir.c | 10 ++++++----
>>  1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/staging/irda/drivers/vlsi_ir.c b/drivers/staging/irda/drivers/vlsi_ir.c
>> index 3dff3c5..20ce4d8 100644
>> --- a/drivers/staging/irda/drivers/vlsi_ir.c
>> +++ b/drivers/staging/irda/drivers/vlsi_ir.c
>> @@ -167,7 +167,8 @@ static void vlsi_proc_pdev(struct seq_file *seq, struct pci_dev *pdev)
>>
>>  	seq_printf(seq, "\n%s (vid/did: [%04x:%04x])\n",
>>  		   pci_name(pdev), (int)pdev->vendor, (int)pdev->device);
>> -	seq_printf(seq, "pci-power-state: %u\n", (unsigned) pdev->current_state);
>> +	seq_printf(seq, "pci-power-state: %d\n",
>> +		   (int __force)pdev->current_state);
>
>Ick, using __force is almost always a huge sign that something is wrong
>here.  This patch does not look correct because of this.
>
>You did read drivers/staging/irda/TODO, right?
>
>thanks,
>
>greg k-h

Good point. This patch can be discarded.

-Matthew