Re: [PATCH v2 4/4] ACPI: PCI: Add generic PCI host controller

From: Sinan Kaya
Date: Thu Apr 14 2016 - 11:59:09 EST


On 4/14/2016 11:53 AM, Sinan Kaya wrote:
> On 4/11/2016 6:45 PM, Jayachandran C wrote:
>> +/* find the entry in cfgarr which contains range bus_start..bus_end */
>> +static int mcfg_lookup(u16 seg, u8 bus_start, u8 bus_end)
>> +{
>> + struct pci_config_window *cfg;
>> + int i;
>> +
>> + if (!cfgarr)
>> + return -ENOENT;
>> +
>> + for (i = 0; cfgarr[i]; i++) {
>> + cfg = cfgarr[i];
>> +
>
> I see that you are allocating an array of cfgarr to keep the MCFG table entries.
> The above way of checking the number of entries is not correct.
>
> You should keep track of the number of entries you found out globally instead of
> relying an element being NULL or not.
>
> If you exceed the array size, you may or may not be lucky to find another entry
> in memory.
>

I see now that you are allocating an extra element in memory. Still, looping to find
out the number of elements didn't quite look good to me.

+ for (i = 0; cfgarr[i]; i++)
+ ;
+ pr_info(PREFIX " MCFG table at loaded, %d entries\n", i);


--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project