From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pf1-x442.google.com ([2607:f8b0:4864:20::442]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1giCHE-0004SN-8f for barebox@lists.infradead.org; Sat, 12 Jan 2019 05:56:24 +0000 Received: by mail-pf1-x442.google.com with SMTP id g62so7919067pfd.12 for ; Fri, 11 Jan 2019 21:56:11 -0800 (PST) From: Andrey Smirnov Date: Fri, 11 Jan 2019 21:55:21 -0800 Message-Id: <20190112055524.7733-16-andrew.smirnov@gmail.com> In-Reply-To: <20190112055524.7733-1-andrew.smirnov@gmail.com> References: <20190112055524.7733-1-andrew.smirnov@gmail.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH v2 15/18] PCI: imx6: Do not switch speed if Gen2 is disabled To: barebox@lists.infradead.org Cc: Andrey Smirnov 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 Signed-off-by: Bjorn Helgaas Reviewed-by: Lucas Stach Cc: yurovsky@gmail.com Cc: Fabio Estevam Cc: Dong Aisheng Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Andrey Smirnov --- drivers/pci/pci-imx6.c | 55 +++++++++++++++++++++--------------------- 1 file 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); -- 2.20.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox