From: Manivannan Sadhasivam Date: Tue, 27 Jun 2023 14:10:36 +0000 (+0530) Subject: PCI: qcom-ep: Switch MHI bus master clock off during L1SS X-Git-Tag: v6.4.16~320 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef2757b1ea8ecdafc6f1c6dd497ac9adb86191ba;p=thirdparty%2Fkernel%2Fstable.git PCI: qcom-ep: Switch MHI bus master clock off during L1SS [ Upstream commit b9cbc06049cb6b7a322d708c2098195fb9fdcc4c ] Currently, as part of the qcom_pcie_perst_deassert() function, instead of writing the updated value to clear PARF_MSTR_AXI_CLK_EN, the variable "val" is re-read. This must be fixed to ensure that the master clock supplied to the MHI bus is correctly gated during L1.1/L1.2 to save power. Thus, replace the line that re-reads "val" with a line that writes the updated value to the register to clear PARF_MSTR_AXI_CLK_EN. [kwilczynski: commit log] Fixes: c457ac029e44 ("PCI: qcom-ep: Gate Master AXI clock to MHI bus during L1SS") Link: https://lore.kernel.org/linux-pci/20230627141036.11600-1-manivannan.sadhasivam@linaro.org Reported-by: Krzysztof Wilczyński Signed-off-by: Manivannan Sadhasivam Signed-off-by: Krzysztof Wilczyński Signed-off-by: Sasha Levin --- diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c index 19b32839ea261..043b356d7d72d 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c @@ -415,7 +415,7 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pci) /* Gate Master AXI clock to MHI bus during L1SS */ val = readl_relaxed(pcie_ep->parf + PARF_MHI_CLOCK_RESET_CTRL); val &= ~PARF_MSTR_AXI_CLK_EN; - val = readl_relaxed(pcie_ep->parf + PARF_MHI_CLOCK_RESET_CTRL); + writel_relaxed(val, pcie_ep->parf + PARF_MHI_CLOCK_RESET_CTRL); dw_pcie_ep_init_notify(&pcie_ep->pci.ep);