From mboxrd@z Thu Jan 1 00:00:00 1970 From: helgaas@kernel.org (Bjorn Helgaas) Date: Tue, 4 Oct 2016 12:40:51 -0500 Subject: ks_dw_pcie_initiate_link_train() question Message-ID: <20161004174051.GE3449@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Murali, This code looks suspicious. Can you comment? void ks_dw_pcie_initiate_link_train(struct keystone_pcie *ks_pcie) { u32 val; /* Disable Link training */ val = readl(ks_pcie->va_app_base + CMD_STATUS); val &= ~LTSSM_EN_VAL; writel(LTSSM_EN_VAL | val, ks_pcie->va_app_base + CMD_STATUS); Here we cleared the LTSSM_EN_VAL bit in "val", but then we add it right back in before writing it back to CMD_STATUS. That looks like a cut and paste error to me, but of course I don't know the hardware. /* Initiate Link Training */ val = readl(ks_pcie->va_app_base + CMD_STATUS); writel(LTSSM_EN_VAL | val, ks_pcie->va_app_base + CMD_STATUS); }