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Date: Thu, 21 Mar 2024 12:21:37 -0400
From: Frank Li <Frank.li@nxp.com>
To: Niklas Cassel <cassel@kernel.org>
Cc: mani@kernel.org, kw@linux.com, niklas.cassel@wdc.com,
	bhelgaas@google.com, gustavo.pimentel@synopsys.com,
	imx@lists.linux.dev, jdmason@kudzu.us, jingoohan1@gmail.com,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	lpieralisi@kernel.org, robh@kernel.org
Subject: Re: [PATCH v2 1/1] PCI: dwc: Fix index 0 incorrectly being
 interpreted as a free ATU slot
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On Thu, Mar 21, 2024 at 09:16:56AM +0100, Niklas Cassel wrote:
> On Wed, Mar 20, 2024 at 10:29:42AM -0400, Frank Li wrote:
> > On Wed, Mar 20, 2024 at 09:53:14AM +0100, Niklas Cassel wrote:
> > > On Wed, Mar 13, 2024 at 12:09:04PM +0100, Niklas Cassel wrote:
> > > > 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@wdc.com>
> > > > > 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@wdc.com>
> > > > > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > > > > ---
> > > > 
> > > > Any chance of this fix being picked up?
> > > 
> > > Gentle ping.
> > 
> > Now it is v6.9 merge windows. You'd better ping two weeks after linus
> > create v6.9-rc1 tag.
> 
> I don't follow this logic.
> Two weeks after v6.9-rc1 is v6.9-rc3.
> Why wait that long to merge a fix?
> 
> The PCI pull request for v6.9-rc1 has already been merged.
> 
> Merging new features (to a submaintainer tree) might temporarily be put
> on hold in relation to the merge window, but for fixes, it is quite
> possible to both queue things (in a submaintainer tree), and to send
> accumulated fixes to Linus during the merge window.
> 
> I did it myself just a few days ago, and Linus pulled it already:
> https://lore.kernel.org/linux-ide/171087658094.21820.15365015832308818327.pr-tracker-bot@kernel.org/T/#t

I am not maintainer of PCI. It was just my observation for pci subsystem.

Frank

> 
> 
> Kind regards,
> Niklas