On 9/4/25 12:32 PM, Marek Vasut wrote: > On 9/4/25 4:40 AM, Damien Le Moal wrote: > > Hello Damien, > >>> @@ -1050,7 +1051,13 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) >>> if (bar == test_reg_bar) >>> continue; >>> - base = pci_epf_alloc_space(epf, bar_size[bar], bar, >>> + test_bar_size = bar_size[bar]; >>> + >>> + bar_fixed_size = epc_features->bar[bar].fixed_size; >>> + if (epc_features->bar[bar].type == BAR_FIXED && bar_fixed_size) >>> + test_bar_size = min(bar_size[bar], bar_fixed_size); >> >> I think this can be simplified to: >> >> if (epc_features->bar[bar].type == BAR_FIXED) >> test_bar_size = epc_features->bar[bar].fixed_size; >> else >> test_bar_size = bar_size[bar]; >> >> because if the bar type is BAR_FIXED, then the size of the bar can only be its >> fixed size. > That is correct, however, please consider the following case: > > - The BAR under test is BAR4 , therefore the size requested by this driver is > bar_size[4] = 131072 Bytes > - The BAR4 on a hypothetical hardware is a fixed size BAR , 262144 Bytes large > > With your proposed change, the "test_bar_size" would end up being 262144 > Bytes , instead of 131072 Bytes without your proposed change , which I think is > not the desired behavior. > > What do you think ? The bar size for the test is arbitrary. If the bar being tested is not a fixed bar, anything is OK. But in the case of a fixed bar, you can only use the fixed bar size so we should force that. -- Damien Le Moal Western Digital Research
