Re: [PATCH v2 2/2] PCI: histb: Correct PCIe reset operation
flat view
From: Shawn Guo <hidden>
Date: 2020-02-27 02:20:04
Also in:
linux-pci
On Wed, Feb 26, 2020 at 7:31 PM Lorenzo Pieralisi [off-list ref] wrote:
On Thu, Jan 09, 2020 at 11:28:51AM +0800, Shawn Guo wrote:quoted
The PCIe reset via GPIO in the driver never worked as expected. Per "Power Sequencing and Reset Signal Timings" table in PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, the PERST# should be deasserted after minimum of 100us once REFCLK is stable. The assertion has been done when the GPIO is being requested, and deassertion should be done in host enabling rather than disabling. Also a bit wait is added to ensure device get ready after reset. Signed-off-by: Shawn Guo <redacted> --- drivers/pci/controller/dwc/pcie-histb.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)Shawn, this looks like a fix, please tag it as such and let me know if it has to be backported, in which case also the previous patch should I assume.
Hi Lorenzo, It is a fix, but we recently realized that the problem needs to be fixed in a way that does not break existing DTB. So please ignore the series for now, and we will try to work out a better one. Sorry that we did not update the thread in time. Shawn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel