Re: [PATCH v2 3/5] PCI: axis: Add ARTPEC-8 PCIe controller driver
From: Wangseok Lee <hidden>
Date: 2022-06-13 01:50:40
Also in:
linux-pci, linux-phy, lkml
On 06/11/2022 00:30, Bjorn Helgaas wrote:
On Fri, Jun 10, 2022 at 09:03:03AM +0900, Wangseok Lee wrote:quoted
On 06/04/2022 01:03, Bjorn Helgaas wrote:quoted
In the subject, why do you tag this "axis"? There's an existing pcie-artpec6.c that uses the driver name ""artpec6-pcie" and the subject line tag "artpec6". This adds pcie-artpec8.c with driver name "artpec8-pcie", so the obvious choice would be "artpec8". I assume you evaluated the possibility of extending artpec6 to support artpec8 in addition to the artpec6 and artpec7 it already supports?"pcie-artpec6. c" supports artpec6 and artpec7 H/W. artpec8 can not be expanded because H/W configuration is completely different from artpec6/7. phy and sub controller are different.Thanks for this detail. Can you include this in the commit log next time around in case anybody else has a similar question?
Ok, sure.
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+/* FSYS SYSREG Offsets */The list below seems to inclue more than just register offsets.Is it clear to change to "FSYS blue logic system registers" like Jasper Nilsson`s comment? https://lore.kernel.org/all/20220607070332.GY18902@axis.com/ (local) My opinion is the same.Yep, that's fine. But spell it "glue logic", not "blue logic" :)
Thanks, it was just a typo.
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+static int artpec8_pcie_get_clk_resources(struct platform_device *pdev, + struct artpec8_pcie *artpec8_ctrl) +{ + struct device *dev = &pdev->dev; + + artpec8_ctrl->pipe_clk = devm_clk_get(dev, "pipe_clk"); + if (IS_ERR(artpec8_ctrl->pipe_clk)) { + dev_err(dev, "couldn't get pipe clock\n"); + return -EINVAL; + } + + artpec8_ctrl->dbi_clk = devm_clk_get(dev, "dbi_clk"); + if (IS_ERR(artpec8_ctrl->dbi_clk)) { + dev_info(dev, "couldn't get dbi clk\n"); + return -EINVAL; + } + + artpec8_ctrl->slv_clk = devm_clk_get(dev, "slv_clk"); + if (IS_ERR(artpec8_ctrl->slv_clk)) { + dev_err(dev, "couldn't get slave clock\n"); + return -EINVAL; + } + + artpec8_ctrl->mstr_clk = devm_clk_get(dev, "mstr_clk"); + if (IS_ERR(artpec8_ctrl->mstr_clk)) { + dev_info(dev, "couldn't get master clk\n");It'd be nice if the err/info messages matched the exact DT name: "pipe_clk", "dbi_clk", slv_clk", etc.I will fix it.quoted
Why are some of the above dev_err() and others dev_info() when you return -EINVAL in all cases?When property is not found, it just to return error. I will modify to return PTR_ERR.Using PTR_ERR() looks like a good idea, since then you return the actual error from devm_clk_get() instead of always returning -EINVAL. But that wasn't my comment. My comment was that it looks like these should be all dev_err() (or all dev_info()).
I understood your question. I think it was simply a way to generate log msg. In this case, is there a more proper print function that use to generate log msg? In addition, error return in artpec8_pcie_get_clk_resources() will be modified to devm_clk_bulk_get(). (according to Krzysztof's review comment.. )
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+ switch (mode) { + case DW_PCIE_RC_TYPE: + artpec8_pcie_writel(artpec8_ctrl->elbi_base, DEVICE_TYPE_RC, + PCIE_ARTPEC8_DEVICE_TYPE); + ret = artpec8_add_pcie_port(artpec8_ctrl, pdev); + if (ret < 0)Are there positive return values that indicate success? Most places above you assume "ret != 0" means failure, so just curious why you test "ret < 0" instead of just "ret".There is no special reason, but it seems that the format used in the existing dw driver is applied.Fair enough. "git grep -A2 add_pcie_port drivers/pci/controller/" says all *_add_pcie_port() calls use the same pattern, so thanks for following that. Bjorn
Thank you for kindness reivew. Best regards, Wangseok Lee