Hi, On Thu, Mar 29, 2018 at 4:04 AM, Manu Gautam <mgautam@xxxxxxxxxxxxxx> wrote: > QMP PHY for USB/PCIE requires pipe_clk for locking of > retime buffers at the pipe interface. Driver checks for > PHY_STATUS without enabling pipe_clk due to which > phy_init() fails with initialization timeout. > Though pipe_clk is output from PHY (after PLL is programmed > during initialization sequence) to GCC clock_ctl and then fed > back to PHY but for PHY_STATUS register to reflect successful > initialization pipe_clk from GCC must be present. > Since, clock driver now ignores status_check for pipe_clk on > clk_enable/disable, driver can safely enable/disable pipe_clk > from phy_init/exit. > > Signed-off-by: Manu Gautam <mgautam@xxxxxxxxxxxxxx> > --- > drivers/phy/qualcomm/phy-qcom-qmp.c | 22 ++++++++-------------- > 1 file changed, 8 insertions(+), 14 deletions(-) Overall this looks much better than the previous version. Thanks! :) I wonder one thing though. You describe the original problem as this: 1. If you don't turn the clock on in qcom_qmp_phy_init() then the PHY never sets the "ready" status. 2. If you don't have the PHY powered on / out of reset (which happens in qcom_qmp_phy_init()) then when you enable/disable the clock it doesn't properly update the status. That's why you needed patch #1 in this series. I wonder: could you solve the above _without_ needing to use BRANCH_HALT_DELAY in the clock driver? Specifically, can you tell me what happens if you put the clk_prepare_enable() after you've powered on the PHY and taken it out of reset but before you check the status? Said another way, put the "clk_prepare_enable(qphy->pipe_clk)" call right before the "readl_poll_timeout" of the ready status? If you do that, you'll turn everything on. Then you'll check that the clock's status is OK and then that the PHY's status is OK. -Doug -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
