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| author | Andrey Smirnov <andrew.smirnov@gmail.com> | 2019-01-16 18:16:57 -0800 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2019-01-18 09:43:10 +0100 |
| commit | 9e343cee2fa2efd416cecf70911a162efcddf32b (patch) | |
| tree | d7d38711e718bd9e4b1a44a896c27fcf05c04e00 /drivers/pci | |
| parent | a93654662b2640aaf4433d15051b0d1ef597ec9d (diff) | |
| download | barebox-9e343cee2fa2efd416cecf70911a162efcddf32b.tar.gz barebox-9e343cee2fa2efd416cecf70911a162efcddf32b.tar.xz | |
PCI: imx6: Do not switch speed if Gen2 is disabled
Port of a Linux commit 93b226f9c65a951a91617f87ba1f05f14e59f26f
Save a bit of time and avoid going through link speed change procedure in
configuration where link max speed is limited to Gen1 in DT.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Cc: yurovsky@gmail.com
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci-imx6.c | 55 |
1 files changed, 28 insertions, 27 deletions
diff --git a/drivers/pci/pci-imx6.c b/drivers/pci/pci-imx6.c index d121a20ce1..6bdc9465db 100644 --- a/drivers/pci/pci-imx6.c +++ b/drivers/pci/pci-imx6.c @@ -496,41 +496,42 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie) tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2; dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp); - } else { - dev_info(dev, "Link: Gen2 disabled\n"); - } - - /* - * Start Directed Speed Change so the best possible speed both link - * partners support can be negotiated. - */ - tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); - tmp |= PORT_LOGIC_SPEED_CHANGE; - dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp); - if (imx6_pcie->variant != IMX7D) { /* - * On i.MX7, DIRECT_SPEED_CHANGE behaves differently - * from i.MX6 family when no link speed transition - * occurs and we go Gen1 -> yep, Gen1. The difference - * is that, in such case, it will not be cleared by HW - * which will cause the following code to report false - * failure. + * Start Directed Speed Change so the best possible + * speed both link partners support can be negotiated. */ + tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); + tmp |= PORT_LOGIC_SPEED_CHANGE; + dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp); + + if (imx6_pcie->variant != IMX7D) { + /* + * On i.MX7, DIRECT_SPEED_CHANGE behaves + * differently from i.MX6 family when no link + * speed transition occurs and we go Gen1 -> + * yep, Gen1. The difference is that, in such + * case, it will not be cleared by HW which + * will cause the following code to report + * false failure. + */ + + ret = imx6_pcie_wait_for_speed_change(imx6_pcie); + if (ret) { + dev_err(dev, "Failed to bring link up!\n"); + goto err_reset_phy; + } + } - ret = imx6_pcie_wait_for_speed_change(imx6_pcie); + /* Make sure link training is finished as well! */ + ret = imx6_pcie_wait_for_link(imx6_pcie); if (ret) { dev_err(dev, "Failed to bring link up!\n"); goto err_reset_phy; } - } - - /* Make sure link training is finished as well! */ - ret = imx6_pcie_wait_for_link(imx6_pcie); - if (ret) { - dev_err(dev, "Failed to bring link up!\n"); - goto err_reset_phy; - } + } else { + dev_info(dev, "Link: Gen2 disabled\n"); + } tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR); dev_info(dev, "Link up, Gen%i\n", (tmp >> 16) & 0xf); |