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Date: Tue, 30 Jan 2024 20:43:24 +0100
From: Niklas Cassel <cassel@kernel.org>
To: Frank Li <Frank.li@nxp.com>
Cc: mani@kernel.org, allenbh@gmail.com, bhelgaas@google.com,
	dave.jiang@intel.com, imx@lists.linux.dev, jdmason@kudzu.us,
	kishon@kernel.org, kw@linux.com, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, lpieralisi@kernel.org,
	ntb@lists.linux.dev
Subject: Re: [PATCH v4 1/1] PCI: endpoint: pci-epf-vntb: Fix transfer failure
 for fixed size BARs
Message-ID: <ZblRXOabZWzRRWoT@x1-carbon>
References: <20240108151015.2030469-1-Frank.Li@nxp.com>
 <ZbJ/P5ldcrSs16q8@lizhi-Precision-Tower-5810>
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In-Reply-To: <ZbJ/P5ldcrSs16q8@lizhi-Precision-Tower-5810>

On Thu, Jan 25, 2024 at 10:33:19AM -0500, Frank Li wrote:
> On Mon, Jan 08, 2024 at 10:10:15AM -0500, Frank Li wrote:
> > For the inbound MEM/IO TLPs, iATU on the endpoint expects the target
> > address to be aligned to the size of the BAR. For configurable BARs, there
> > is no issue because both host and endpoint will know the exact size of the
> > BAR region. But for fixed size BARs available in some controllers, if the
> > BAR size advertised by the endpoint is not same as of the actual BAR size
> > used in the controller, then the MEM/IO TLPs generated by the host will not
> > be translated properly by the endpoint iATU.
> > 
> > So if the fixed size BARs are available in endpoint controllers, always use
> > the actual BAR size.
> > 
> > This only fixes doorbell (DB) BAR. A similar fix is needed for memory map
> > windows(MW) BARs.
> > 
> > Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
> > Cc: stable@vger.kernel.org
> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> 
> @lpieralisi:
> 
> 	Could you please pick this fix patch?


Hello Frank, Lorenzo, Mani,


Frank, sorry for not seeing this patch earlier.

Could you please see if this series fixes your issue:
https://lore.kernel.org/linux-pci/20240130193214.713739-1-cassel@kernel.org/T/#t

I think it is nicer since:
1) It doesn't add copy pasted code from pci-epf-test.c to pci-epf-vntb.c.
2) I would expect it to handle both the doorbell BAR and the MW BARs.


Kind regards,
Niklas