Commit bdfc7b55 authored by Mina Almasry's avatar Mina Almasry Committed by Tony Nguyen
Browse files

idpf: read lower clock bits inside the time sandwich 



PCIe reads need to be done inside the time sandwich because PCIe
writes may get buffered in the PCIe fabric and posted to the device
after the _postts completes. Doing the PCIe read inside the time
sandwich guarantees that the write gets flushed before the _postts
timestamp is taken.

Cc: lrizzo@google.com
Cc: namangulati@google.com
Cc: willemb@google.com
Cc: intel-wired-lan@lists.osuosl.org
Cc: milena.olech@intel.com
Cc: jacob.e.keller@intel.com

Fixes: 5cb8805d ("idpf: negotiate PTP capabilities and get PTP clock")
Suggested-by: default avatarShachar Raindel <shacharr@google.com>
Signed-off-by: default avatarMina Almasry <almasrymina@google.com>
Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Reviewed-by: default avatarAleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: default avatarSamuel Salin <Samuel.salin@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent d3f867e7

drivers/net/ethernet/intel/idpf/idpf_ptp.c

+1 −1
Original line number Diff line number Diff line
@@ -108,11 +108,11 @@ static u64 idpf_ptp_read_src_clk_reg_direct(struct idpf_adapter *adapter, 
	ptp_read_system_prets(sts);



	idpf_ptp_enable_shtime(adapter);

	lo = readl(ptp->dev_clk_regs.dev_clk_ns_l);



	/* Read the system timestamp post PHC read */

	ptp_read_system_postts(sts);



	lo = readl(ptp->dev_clk_regs.dev_clk_ns_l);

	hi = readl(ptp->dev_clk_regs.dev_clk_ns_h);



	spin_unlock(&ptp->read_dev_clk_lock);