On Thu 31 May 04:45 PDT 2018, Greg Kroah-Hartman wrote:
On Thu, May 31, 2018 at 01:21:56PM +0200, Sebastian Gottschall wrote:
Am 28.05.2018 um 12:05 schrieb Greg Kroah-Hartman:
4.16-stable review patch. If anyone has any objections, please let me know.
From: Bjorn Andersson bjorn.andersson@linaro.org
[ Upstream commit a7aa75a2a7dba32594291a71c3704000a2fd7089 ]
The base of the TLMM gpiochip should not be statically defined as 0, fix this to not artificially restrict the existence of multiple pinctrl-msm devices.
Fixes: f365be092572 ("pinctrl: Add Qualcomm TLMM driver") Reported-by: Timur Tabi timur@codeaurora.org Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
drivers/pinctrl/qcom/pinctrl-msm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/pinctrl/qcom/pinctrl-msm.c +++ b/drivers/pinctrl/qcom/pinctrl-msm.c @@ -818,7 +818,7 @@ static int msm_gpio_init(struct msm_pinc return -EINVAL; chip = &pctrl->chip;
- chip->base = 0;
- chip->base = -1; chip->ngpio = ngpio; chip->label = dev_name(pctrl->dev); chip->parent = pctrl->dev;
this patch creates a regression for me. on ipq8064 the systems gpios now start somewhere in the sky
new layout
lrwxrwxrwx 1 root root 0 Jan 1 00:00 gpiochip373 -> ../../devices/platform/soc/1b700000.pci/pci0001:00/0001:00:00.0/0001:01:00.0/gpio/gpiochip373 lrwxrwxrwx 1 root root 0 Jan 1 00:00 gpiochip408 -> ../../devices/platform/soc/1b500000.pci/pci0000:00/0000:00:00.0/0000:01:00.0/gpio/gpiochip408 lrwxrwxrwx 1 root root 0 Jan 1 00:00 gpiochip443 -> ../../devices/platform/soc/800000.pinmux/gpio/gpiochip443
before the patch
lrwxrwxrwx 1 root root 0 Jan 1 1970 gpiochip0 -> ../../devices/platform/soc/800000.pinmux/gpio/gpiochip0 lrwxrwxrwx 1 root root 0 May 31 13:13 gpiochip442 -> ../../devices/platform/soc/1b700000.pci/pci0001:00/0001:00:00.0/0001:01:00.0/gpio/gpiochip442 lrwxrwxrwx 1 root root 0 May 31 13:13 gpiochip477 -> ../../devices/platform/soc/1b500000.pci/pci0000:00/0000:00:00.0/0000:01:00.0/gpio/gpiochip477
this broke my userspace gpio handling. i can override this, but still it doesnt look correct since there is a hole at the beginng likelly reserved by unused arm gpios
So does this mean that 4.17-rc is also broken for you? If so, this needs to be reverted there as well.
Bjorn, any ideas?
The Qualcomm TLMM (pinctrl) driver was introduced long after it was decided that the kernel should not rely on global/static gpio numbering.
But due to a mistake on my part the dynamic gpio base for this gpiochip was always 0, which the offending patch corrects.
So writing user space code relying on the gpio numbering for this chip has always been incorrect, just as it is for the other two gpiochips listed above.
The original objection for backporting this patch was a touchscreen driver stopped working on 4.4, but the driver clearly doesn't depend on global or static numbering of gpios. I don't think this was ever root caused.
I guess the pragmatic approach would be to come up with something like Timur's suggested fix that makes the first instance of this driver use base = 0 and then use dynamic numbering for the rest, to maintain support for this incorrect usage of the gpio sysfs interface. (Although that would probably break if Timur's customers move their user space to the new platform as "the first instance" isn't deterministic).
Regards, Bjorn