linux/drivers/pinctrl/devicetree.c

427 lines
11 KiB

pinctrl: Don't just pretend to protect pinctrl_maps, do it for real Way back, when the world was a simpler place and there was no war, no evil, and no kernel bugs, there was just a single pinctrl lock. That was how the world was when (57291ce pinctrl: core device tree mapping table parsing support) was written. In that case, there were instances where the pinctrl mutex was already held when pinctrl_register_map() was called, hence a "locked" parameter was passed to the function to indicate that the mutex was already locked (so we shouldn't lock it again). A few years ago in (42fed7b pinctrl: move subsystem mutex to pinctrl_dev struct), we switched to a separate pinctrl_maps_mutex. ...but (oops) we forgot to re-think about the whole "locked" parameter for pinctrl_register_map(). Basically the "locked" parameter appears to still refer to whether the bigger pinctrl_dev mutex is locked, but we're using it to skip locks of our (now separate) pinctrl_maps_mutex. That's kind of a bad thing(TM). Probably nobody noticed because most of the calls to pinctrl_register_map happen at boot time and we've got synchronous device probing. ...and even cases where we're asynchronous don't end up actually hitting the race too often. ...but after banging my head against the wall for a bug that reproduced 1 out of 1000 reboots and lots of looking through kgdb, I finally noticed this. Anyway, we can now safely remove the "locked" parameter and go back to a war-free, evil-free, and kernel-bug-free world. Fixes: 42fed7ba44e4 ("pinctrl: move subsystem mutex to pinctrl_dev struct") Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-01 09:01:27 -07:00
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-07 13:51:33 -03:00
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-07 13:51:33 -03:00
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-07 13:51:33 -03:00
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-07 13:51:33 -03:00