Re: [PATCH v2 1/1] PCI: dwc: Fix index 0 incorrectly being interpreted as a free ATU slot

[Niklas Cassel]

On Mon, Mar 04, 2024 at 05:46:16PM -0500, Frank Li wrote:
> dw_pcie_ep_inbound_atu()
> {
> 	...
> 	if (!ep->bar_to_atu[bar])
> 		free_win = find_first_zero_bit(ep->ib_window_map, pci->num_ib_windows);
> 	else
> 		free_win = ep->bar_to_atu[bar];
> 	...
> }
> 
> The atu index 0 is valid case for atu number. The find_first_zero_bit()
> will return 6 when second time call into this function if atu is 0. Suppose
> it should use branch 'free_win = ep->bar_to_atu[bar]'.
> 
> Change 'bar_to_atu' to free_win + 1. Initialize bar_to_atu as 0 to indicate
> it have not allocate atu to the bar.
> 
> Reported-by: Niklas Cassel <Niklas.Cassel@xxxxxxx>
> Closes: https://lore.kernel.org/linux-pci/ZXt2A+Fusfz3luQV@x1-carbon/T/#u
> Fixes: 4284c88fff0e ("PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address")
> Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx>
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>

Tested-by: Niklas Cassel <niklas.cassel@xxxxxxx>