Hi, On Fri, Mar 13, 2020 at 9:09 PM Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx> wrote: > > Some time ago Greg Ungerer reported some random hangs using > the staging mt7621-pci driver: > > See: > * http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2019-June/134947.html > > Try to fix that is the main motivation of this patch series. > > Also in openwrt there is a driver for mt7621-pci which seems was rewritten > from scratch (for kernel 4.14) by Ryder Lee and Weijie Gao from mediatek. > There the approach for reset assert-deassert process is to set as 'gpio' > the function for all the 'pcie' group for the pinctrl driver and use those > gpio's as a reset for the end points. The driver I am talking about is still > using legacy pci and legacy gpio kernel interfaces. IMHO, the correct thing > to do is make this staging driver properly clean and functional and put it > in its correct place in the mainline. > > See: > * https://gist.github.com/dengqf6/7a9e9b4032d99f1a91dd9256c8a65c36 > > Because of all of this this patch series tries to avoid random hangs of boot > trying to use the 'reset-gpios' approach. > > Changes are being tested by openwrt people and seems to work. > > Hope this helps. > > Changes in v4: > * Make use of 'devm_gpiod_get_index_optional' instead of 'devm_gpiod_get_index'. > * Use 'dev_err' instead of 'dev_notice' and return ERR_PTR if > 'devm_gpiod_get_index_optional' fails. > * Rename pers dealy macro to PERST_DELAY_MS. > * Add new patch 6 which removes function 'mt7621_reset_port' not needed anymore. It seems this series work but due to an unknow bug set / clear gpio registers are not properly working. So maybe this patch is also necessary: https://github.com/openwrt/openwrt/pull/2798/commits/823d41e28b4e15734560508b29df726b16c51dab Should this patch be also properly added to the tree? Added Linus Walleij and René van Dorst in order to get feedback about this issue. I also add all the thread to get openwrt working with 5.4 in where this patches and the gpio one have been added (just in case is interesting for anyone): https://github.com/openwrt/openwrt/pull/2798 Best regards, Sergio Paracuellos > > Changes in v3: > * Avoid to fail if gpio descriptor fails on get. > * re-do PATCH 1 commit message. > * Take into account gpio low polarity on request and assert and deassert. > * Review error path of driver to properly release gpio's resources. > > Changes in v2: > * restore configuration for pers mode to GPIO. > * Avoid to read FTS_NUM register in reset state. > * Release gpio's patch added > > Best regards, > Sergio Paracuellos > > > Sergio Paracuellos (6): > staging: mt7621-pci: use gpios for properly reset > staging: mt7621-pci: change value for 'PERST_DELAY_MS' > staging: mt7621-dts: make use of 'reset-gpios' property for pci > staging: mt7621-pci: bindings: update doc accordly to last changes > staging: mt7621-pci: release gpios after pci initialization > staging: mt7621-pci: delete no more needed 'mt7621_reset_port' > > drivers/staging/mt7621-dts/mt7621.dtsi | 11 +- > .../mt7621-pci/mediatek,mt7621-pci.txt | 7 +- > drivers/staging/mt7621-pci/pci-mt7621.c | 122 ++++++++++-------- > 3 files changed, 82 insertions(+), 58 deletions(-) > > -- > 2.25.1 > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
