Re: [PATCH] PCI: Add PCI_EXP_DEVCTL_PAYLOAD_* macros

From: "Pali Rohár" <pali@kernel.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI: Add PCI_EXP_DEVCTL_PAYLOAD_* macros
Date: Wed, 14 Apr 2021 22:24:22 +0200	[thread overview]
Message-ID: <20210414202422.54dvjd74so45hhcl@pali> (raw)
In-Reply-To: <20210414202309.GA2533708@bjorn-Precision-5520>

On Wednesday 14 April 2021 15:23:09 Bjorn Helgaas wrote:
> On Tue, Apr 13, 2021 at 10:39:16AM +0200, Pali Rohár wrote:
> > On Monday 12 April 2021 14:27:40 Bjorn Helgaas wrote:
> > > On Mon, Apr 12, 2021 at 02:46:02PM +0200, Pali Rohár wrote:
> > > > Define new PCI_EXP_DEVCTL_PAYLOAD_* macros in linux/pci_regs.h header file
> > > > for Max Payload Size. Macros are defined in the same style as existing
> > > > macros PCI_EXP_DEVCTL_READRQ_* macros.
> > > > 
> > > > Signed-off-by: Pali Rohár <pali@kernel.org>
> > > > ---
> > > >  include/uapi/linux/pci_regs.h | 6 ++++++
> > > >  1 file changed, 6 insertions(+)
> > > > 
> > > > diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> > > > index e709ae8235e7..8f1b15eea53e 100644
> > > > --- a/include/uapi/linux/pci_regs.h
> > > > +++ b/include/uapi/linux/pci_regs.h
> > > > @@ -504,6 +504,12 @@
> > > >  #define  PCI_EXP_DEVCTL_URRE	0x0008	/* Unsupported Request Reporting En. */
> > > >  #define  PCI_EXP_DEVCTL_RELAX_EN 0x0010 /* Enable relaxed ordering */
> > > >  #define  PCI_EXP_DEVCTL_PAYLOAD	0x00e0	/* Max_Payload_Size */
> > > > +#define  PCI_EXP_DEVCTL_PAYLOAD_128B 0x0000 /* 128 Bytes */
> > > > +#define  PCI_EXP_DEVCTL_PAYLOAD_256B 0x0020 /* 256 Bytes */
> > > > +#define  PCI_EXP_DEVCTL_PAYLOAD_512B 0x0040 /* 512 Bytes */
> > > > +#define  PCI_EXP_DEVCTL_PAYLOAD_1024B 0x0060 /* 1024 Bytes */
> > > > +#define  PCI_EXP_DEVCTL_PAYLOAD_2048B 0x0080 /* 2048 Bytes */
> > > > +#define  PCI_EXP_DEVCTL_PAYLOAD_4096B 0x00A0 /* 4096 Bytes */
> > > 
> > > This is fine if we're going to use them, but we generally don't add
> > > definitions purely for documentation.
> > > 
> > > 5929b8a38ce0 ("PCI: Add defines for PCIe Max_Read_Request_Size") added
> > > the PCI_EXP_DEVCTL_READRQ_* definitions and we do have a few (very
> > > few) uses in drivers.
> > 
> > I'm planning to use this constant to fix pci-aardvark.c driver. Aardvark
> > changes are not ready yet, but I'm preparing them in my git tree
> > https://git.kernel.org/pub/scm/linux/kernel/git/pali/linux.git/log/?h=pci-aardvark
> > (commit PCI: aardvark: Fix PCIe Max Payload Size setting)
> > 
> > But as this is not change in aardvark driver, I sent it separately and
> > earlier. As it would be dependency for aardvark changes.
> 
> OK, just include this in that series.

Ok, fine.