From 90d4e466c9ea2010f33880a36317a8486ccbe082 Mon Sep 17 00:00:00 2001 Message-ID: <90d4e466c9ea2010f33880a36317a8486ccbe082.1736960708.git.lorenzo@kernel.org> In-Reply-To: <0e7a622da17da0042294860cdb7a2fac091d25b1.1736960708.git.lorenzo@kernel.org> References: <0e7a622da17da0042294860cdb7a2fac091d25b1.1736960708.git.lorenzo@kernel.org> From: Lorenzo Bianconi Date: Wed, 8 Jan 2025 10:50:43 +0100 Subject: [PATCH 4/6] PCI: mediatek-gen3: Move reset delay in mtk_pcie_en7581_power_up() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Airoha EN7581 has a hw bug asserting/releasing PCIE_PE_RSTB signal causing occasional PCIe link down issues. In order to overcome the problem, PCIe block is reset using REG_PCI_CONTROL (0x88) and REG_RESET_CONTROL (0x834) registers available in the clock module running clk_bulk_prepare_enable() in mtk_pcie_en7581_power_up(). In order to make the code more readable, move the wait for the time needed to complete the PCIe reset from en7581_pci_enable() to mtk_pcie_en7581_power_up(). Reduce reset timeout from 250ms to the standard PCIE_T_PVPERL_MS value (100ms) since it has no impact on the driver behavior. Link: https://lore.kernel.org/r/20250108-pcie-en7581-fixes-v6-4-21ac939a3b9b@kernel.org Signed-off-by: Lorenzo Bianconi Signed-off-by: Krzysztof Wilczyński Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: Manivannan Sadhasivam Acked-by: Stephen Boyd --- drivers/clk/clk-en7523.c | 1 - drivers/pci/controller/pcie-mediatek-gen3.c | 7 +++++++ 2 files changed, 7 insertions(+), 1 deletion(-) --- a/drivers/clk/clk-en7523.c +++ b/drivers/clk/clk-en7523.c @@ -489,7 +489,6 @@ static int en7581_pci_enable(struct clk_ REG_PCI_CONTROL_PERSTOUT; val = readl(np_base + REG_PCI_CONTROL); writel(val | mask, np_base + REG_PCI_CONTROL); - msleep(250); return 0; } --- a/drivers/pci/controller/pcie-mediatek-gen3.c +++ b/drivers/pci/controller/pcie-mediatek-gen3.c @@ -936,6 +936,13 @@ static int mtk_pcie_en7581_power_up(stru goto err_clk_prepare_enable; } + /* + * Airoha EN7581 performs PCIe reset via clk callbacks since it has a + * hw issue with PCIE_PE_RSTB signal. Add wait for the time needed to + * complete the PCIe reset. + */ + msleep(PCIE_T_PVPERL_MS); + return 0; err_clk_prepare_enable: