Re: [RESEND v4 1/6] misc: Add Synopsys DesignWare xData IP driver

From: "Krzysztof Wilczyński" <kw@linux.com>
To: Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>
Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Derek Kiernan <derek.kiernan@xilinx.com>,
	Dragan Cvetic <dragan.cvetic@xilinx.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Bjorn Helgaas <helgaas@kernel.org>
Subject: Re: [RESEND v4 1/6] misc: Add Synopsys DesignWare xData IP driver
Date: Mon, 8 Feb 2021 23:53:54 +0100	[thread overview]
Message-ID: <YCHBAmFAOv/Joqp5@rocinante> (raw)
In-Reply-To: <DM5PR12MB18354765D69889F2CD6E4D89DA8F9@DM5PR12MB1835.namprd12.prod.outlook.com>

[+cc Bjorn]

Hi Gustavo,

[...]
> Thanks for your review. I will wait for a couple of days, before sending 
> a new version of this patch series based on your feedback.

Thank you!

There might be one more change, and improvement, to be done as per
Bjorn's feedback, see:

  https://lore.kernel.org/linux-pci/20210208193516.GA406304@bjorn-Precision-5520/

The code in question would be (exceprt from the patch):

[...]
+static int dw_xdata_pcie_probe(struct pci_dev *pdev,
+			       const struct pci_device_id *pid)
+{
+	const struct dw_xdata_pcie_data *pdata = (void *)pid->driver_data;
+	struct dw_xdata *dw;
[...]
+	dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
+	if (!dw->rg_region.vaddr)
+		return -ENOMEM;
[...]

Perhaps something like the following would would?

void __iomem * const *iomap_table;

iomap_table = pcim_iomap_table(pdev);
if (!iomap_table)
        return -ENOMEM;

dw->rg_region.vaddr = iomap_table[pdata->rg_bar];
if (!dw->rg_region.vaddr)
	return -ENOMEM;

With sensible error messages added, of course.  What do you think?

Krzysztof