On 9/29/2022 7:34 AM, Han Jingoo wrote:
External email: Use caution opening links or attachments On Mon, Sep 26, 2022, Vidya Sagar <vidyas@xxxxxxxxxx> wrote:commit aeaa0bfe89654 ("PCI: dwc: Move N_FTS setup to common setup") incorrectly uses pci->link_gen in deriving the index to the n_fts[] array also introducing the issue of accessing beyond the boundaries of array for greater than Gen-2 speeds. This change fixes that issue.Dear Vidya, I am just ok with this patch. By the way, do we need another patch to generalize this setting? Currently, this code targets only Gen1 and Gen2. But, in my opinion, it is possible that this driver can be used for more than Gen2, later. PCIe Gen6 standard is available and Synopsys has their solution for Gen6. So, would you send a new patch to generalize this thing, later? Thank you.
As I mentioned in the commit message, current code is incorrectly using 'gen' in the index and ideally n_fts programming has nothing to do with the speed and hence I tried to remove the 'gen' reference in the current patch. So, the same code (after applying this patch) should work for any future Synopsys IP versions supporting higher speeds.
Thanks, Vidya Sagar
Best regards, Jingoo HanFixes: aeaa0bfe8965 ("PCI: dwc: Move N_FTS setup to common setup") Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx> Acked-by: Jingoo Han <jingoohan1@xxxxxxxxx> --- V2: * Addressed review comments from Bjorn * Added "Acked-by: Jingoo Han <jingoohan1@xxxxxxxxx>" drivers/pci/controller/dwc/pcie-designware.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 650a7f22f9d0..3df687667f27 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -649,7 +649,7 @@ void dw_pcie_setup(struct dw_pcie *pci) if (pci->n_fts[1]) { val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); val &= ~PORT_LOGIC_N_FTS_MASK; - val |= pci->n_fts[pci->link_gen - 1]; + val |= pci->n_fts[1]; dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val); } -- 2.17.1
