Message ID | 20190325194319.12850-1-marek.vasut@gmail.com (mailing list archive) |
---|---|
State | Accepted, archived |
Commit | be20bbcb0a8cb5597cc62b3e28d275919f3431df |
Headers | show |
Series | [V3] PCI: rcar: Add the initialization of PCIe link in resume_noirq() | expand |
On Mon, Mar 25, 2019 at 8:43 PM <marek.vasut@gmail.com> wrote: > From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > > Reestablish the PCIe link very early in the resume process in case it > went down to prevent PCI accesses from hanging the bus. Such accesses > can happen early in the PCI resume process, as early as the > SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the > driver resume_noirq() callback. > > Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar") > Signed-off-by: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com> > Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> > [lorenzo.pieralisi@arm.com: reformatted commit log] > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Reviewed-by: Simon Horman <horms+renesas@verge.net.au> > Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert
On Mon, Mar 25, 2019 at 08:43:19PM +0100, marek.vasut@gmail.com wrote: > From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > > Reestablish the PCIe link very early in the resume process in case it > went down to prevent PCI accesses from hanging the bus. Such accesses > can happen early in the PCI resume process, as early as the > SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the > driver resume_noirq() callback. > > Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar") > Signed-off-by: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com> > Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> > [lorenzo.pieralisi@arm.com: reformatted commit log] > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Reviewed-by: Simon Horman <horms+renesas@verge.net.au> > Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > Cc: stable@vger.kernel.org > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > Cc: Phil Edworthy <phil.edworthy@renesas.com> > Cc: Simon Horman <horms+renesas@verge.net.au> > Cc: Wolfram Sang <wsa@the-dreams.de> > Cc: linux-renesas-soc@vger.kernel.org > --- > V2: - Use BIT() macro for (1 << n) > - Since polling in rcar_pcie_wait_for_dl() uses udelay(), do not > add extra changes to this function anymore > - Make resume_noirq return early and clean up parenthesis therein > V3: - Add missing PMSR register definition, dropped due to patch reshuffling > --- > drivers/pci/controller/pcie-rcar.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) Applied to pci/controller-fixes for one of the upcoming -rc*. Thanks, Lorenzo > diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c > index c8febb009454..6a4e435bd35f 100644 > --- a/drivers/pci/controller/pcie-rcar.c > +++ b/drivers/pci/controller/pcie-rcar.c > @@ -46,6 +46,7 @@ > > /* Transfer control */ > #define PCIETCTLR 0x02000 > +#define DL_DOWN BIT(3) > #define CFINIT 1 > #define PCIETSTR 0x02004 > #define DATA_LINK_ACTIVE 1 > @@ -94,6 +95,7 @@ > #define MACCTLR 0x011058 > #define SPEED_CHANGE BIT(24) > #define SCRAMBLE_DISABLE BIT(27) > +#define PMSR 0x01105c > #define MACS2R 0x011078 > #define MACCGSPSETR 0x011084 > #define SPCNGRSN BIT(31) > @@ -1130,6 +1132,7 @@ static int rcar_pcie_probe(struct platform_device *pdev) > pcie = pci_host_bridge_priv(bridge); > > pcie->dev = dev; > + platform_set_drvdata(pdev, pcie); > > err = pci_parse_request_of_pci_ranges(dev, &pcie->resources, NULL); > if (err) > @@ -1221,10 +1224,28 @@ static int rcar_pcie_probe(struct platform_device *pdev) > return err; > } > > +static int rcar_pcie_resume_noirq(struct device *dev) > +{ > + struct rcar_pcie *pcie = dev_get_drvdata(dev); > + > + if (rcar_pci_read_reg(pcie, PMSR) && > + !(rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN)) > + return 0; > + > + /* Re-establish the PCIe link */ > + rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR); > + return rcar_pcie_wait_for_dl(pcie); > +} > + > +static const struct dev_pm_ops rcar_pcie_pm_ops = { > + .resume_noirq = rcar_pcie_resume_noirq, > +}; > + > static struct platform_driver rcar_pcie_driver = { > .driver = { > .name = "rcar-pcie", > .of_match_table = rcar_pcie_of_match, > + .pm = &rcar_pcie_pm_ops, > .suppress_bind_attrs = true, > }, > .probe = rcar_pcie_probe, > -- > 2.20.1 >
On Mon, Mar 25, 2019 at 08:43:19PM +0100, marek.vasut@gmail.com wrote: > From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > > Reestablish the PCIe link very early in the resume process in case it > went down to prevent PCI accesses from hanging the bus. Such accesses > can happen early in the PCI resume process, as early as the > SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the > driver resume_noirq() callback. > > Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar") I'm fine with the fix itself, but since e015f88c368d appeared more than two years ago in v4.5, the justification for merging this after the merge window is a little weak. Is there a more recent change that exposed this problem? The usual situation is that we merged something during the v5.1 merge window that caused a regression, and we're now fixing that before v5.1 final. Bjorn > Signed-off-by: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com> > Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> > [lorenzo.pieralisi@arm.com: reformatted commit log] > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Reviewed-by: Simon Horman <horms+renesas@verge.net.au> > Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > Cc: stable@vger.kernel.org > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > Cc: Phil Edworthy <phil.edworthy@renesas.com> > Cc: Simon Horman <horms+renesas@verge.net.au> > Cc: Wolfram Sang <wsa@the-dreams.de> > Cc: linux-renesas-soc@vger.kernel.org > --- > V2: - Use BIT() macro for (1 << n) > - Since polling in rcar_pcie_wait_for_dl() uses udelay(), do not > add extra changes to this function anymore > - Make resume_noirq return early and clean up parenthesis therein > V3: - Add missing PMSR register definition, dropped due to patch reshuffling > --- > drivers/pci/controller/pcie-rcar.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c > index c8febb009454..6a4e435bd35f 100644 > --- a/drivers/pci/controller/pcie-rcar.c > +++ b/drivers/pci/controller/pcie-rcar.c > @@ -46,6 +46,7 @@ > > /* Transfer control */ > #define PCIETCTLR 0x02000 > +#define DL_DOWN BIT(3) > #define CFINIT 1 > #define PCIETSTR 0x02004 > #define DATA_LINK_ACTIVE 1 > @@ -94,6 +95,7 @@ > #define MACCTLR 0x011058 > #define SPEED_CHANGE BIT(24) > #define SCRAMBLE_DISABLE BIT(27) > +#define PMSR 0x01105c > #define MACS2R 0x011078 > #define MACCGSPSETR 0x011084 > #define SPCNGRSN BIT(31) > @@ -1130,6 +1132,7 @@ static int rcar_pcie_probe(struct platform_device *pdev) > pcie = pci_host_bridge_priv(bridge); > > pcie->dev = dev; > + platform_set_drvdata(pdev, pcie); > > err = pci_parse_request_of_pci_ranges(dev, &pcie->resources, NULL); > if (err) > @@ -1221,10 +1224,28 @@ static int rcar_pcie_probe(struct platform_device *pdev) > return err; > } > > +static int rcar_pcie_resume_noirq(struct device *dev) > +{ > + struct rcar_pcie *pcie = dev_get_drvdata(dev); > + > + if (rcar_pci_read_reg(pcie, PMSR) && > + !(rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN)) > + return 0; > + > + /* Re-establish the PCIe link */ > + rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR); > + return rcar_pcie_wait_for_dl(pcie); > +} > + > +static const struct dev_pm_ops rcar_pcie_pm_ops = { > + .resume_noirq = rcar_pcie_resume_noirq, > +}; > + > static struct platform_driver rcar_pcie_driver = { > .driver = { > .name = "rcar-pcie", > .of_match_table = rcar_pcie_of_match, > + .pm = &rcar_pcie_pm_ops, > .suppress_bind_attrs = true, > }, > .probe = rcar_pcie_probe, > -- > 2.20.1 >
On Thu, Mar 28, 2019 at 09:18:22AM -0500, Bjorn Helgaas wrote: > On Mon, Mar 25, 2019 at 08:43:19PM +0100, marek.vasut@gmail.com wrote: > > From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > > > > Reestablish the PCIe link very early in the resume process in case it > > went down to prevent PCI accesses from hanging the bus. Such accesses > > can happen early in the PCI resume process, as early as the > > SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the > > driver resume_noirq() callback. > > > > Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar") > > I'm fine with the fix itself, but since e015f88c368d appeared more > than two years ago in v4.5, the justification for merging this after > the merge window is a little weak. > > Is there a more recent change that exposed this problem? The usual > situation is that we merged something during the v5.1 merge window > that caused a regression, and we're now fixing that before v5.1 final. I do not think that's urgent enough to merge it in one of the -rc* but I won't speak for the authors - it will trickle back anyway through the stable mechanism, I just queued it as a fix since that's how it qualifies. So postponing it to v5.2 is fine by me, just let me know how it is best to handle it. Thanks, Lorenzo > Bjorn > > > Signed-off-by: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > > Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com> > > Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> > > [lorenzo.pieralisi@arm.com: reformatted commit log] > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Reviewed-by: Simon Horman <horms+renesas@verge.net.au> > > Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > > Cc: stable@vger.kernel.org > > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > > Cc: Phil Edworthy <phil.edworthy@renesas.com> > > Cc: Simon Horman <horms+renesas@verge.net.au> > > Cc: Wolfram Sang <wsa@the-dreams.de> > > Cc: linux-renesas-soc@vger.kernel.org > > --- > > V2: - Use BIT() macro for (1 << n) > > - Since polling in rcar_pcie_wait_for_dl() uses udelay(), do not > > add extra changes to this function anymore > > - Make resume_noirq return early and clean up parenthesis therein > > V3: - Add missing PMSR register definition, dropped due to patch reshuffling > > --- > > drivers/pci/controller/pcie-rcar.c | 21 +++++++++++++++++++++ > > 1 file changed, 21 insertions(+) > > > > diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c > > index c8febb009454..6a4e435bd35f 100644 > > --- a/drivers/pci/controller/pcie-rcar.c > > +++ b/drivers/pci/controller/pcie-rcar.c > > @@ -46,6 +46,7 @@ > > > > /* Transfer control */ > > #define PCIETCTLR 0x02000 > > +#define DL_DOWN BIT(3) > > #define CFINIT 1 > > #define PCIETSTR 0x02004 > > #define DATA_LINK_ACTIVE 1 > > @@ -94,6 +95,7 @@ > > #define MACCTLR 0x011058 > > #define SPEED_CHANGE BIT(24) > > #define SCRAMBLE_DISABLE BIT(27) > > +#define PMSR 0x01105c > > #define MACS2R 0x011078 > > #define MACCGSPSETR 0x011084 > > #define SPCNGRSN BIT(31) > > @@ -1130,6 +1132,7 @@ static int rcar_pcie_probe(struct platform_device *pdev) > > pcie = pci_host_bridge_priv(bridge); > > > > pcie->dev = dev; > > + platform_set_drvdata(pdev, pcie); > > > > err = pci_parse_request_of_pci_ranges(dev, &pcie->resources, NULL); > > if (err) > > @@ -1221,10 +1224,28 @@ static int rcar_pcie_probe(struct platform_device *pdev) > > return err; > > } > > > > +static int rcar_pcie_resume_noirq(struct device *dev) > > +{ > > + struct rcar_pcie *pcie = dev_get_drvdata(dev); > > + > > + if (rcar_pci_read_reg(pcie, PMSR) && > > + !(rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN)) > > + return 0; > > + > > + /* Re-establish the PCIe link */ > > + rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR); > > + return rcar_pcie_wait_for_dl(pcie); > > +} > > + > > +static const struct dev_pm_ops rcar_pcie_pm_ops = { > > + .resume_noirq = rcar_pcie_resume_noirq, > > +}; > > + > > static struct platform_driver rcar_pcie_driver = { > > .driver = { > > .name = "rcar-pcie", > > .of_match_table = rcar_pcie_of_match, > > + .pm = &rcar_pcie_pm_ops, > > .suppress_bind_attrs = true, > > }, > > .probe = rcar_pcie_probe, > > -- > > 2.20.1 > >
Hi Bjorn, On Thu, Mar 28, 2019 at 3:18 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > On Mon, Mar 25, 2019 at 08:43:19PM +0100, marek.vasut@gmail.com wrote: > > From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > > > > Reestablish the PCIe link very early in the resume process in case it > > went down to prevent PCI accesses from hanging the bus. Such accesses > > can happen early in the PCI resume process, as early as the > > SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the > > driver resume_noirq() callback. > > > > Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar") > > I'm fine with the fix itself, but since e015f88c368d appeared more > than two years ago in v4.5, the justification for merging this after > the merge window is a little weak. V1 of this fix was posted in November 2017, but IIRC, the series became the target of some bike-shedding... > Is there a more recent change that exposed this problem? The usual > situation is that we merged something during the v5.1 merge window > that caused a regression, and we're now fixing that before v5.1 final. There are several reasons most people couldn't even run suspend/resume cycles on their systems: 1. Early releases of the affected boards came with firmware revisions with non-functional PSCI system suspend, 2. Preparing the PMIC for suspend required ugly assistance from i2cset in userspace, until the Linux driver learned to take care of that itself in v4.18/v4.19. I guess the fix can survive postponing to v5.2, though... Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Thu, Mar 28, 2019 at 03:59:11PM +0100, Geert Uytterhoeven wrote: > On Thu, Mar 28, 2019 at 3:18 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Mon, Mar 25, 2019 at 08:43:19PM +0100, marek.vasut@gmail.com wrote: > > > From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> > > > > > > Reestablish the PCIe link very early in the resume process in case it > > > went down to prevent PCI accesses from hanging the bus. Such accesses > > > can happen early in the PCI resume process, as early as the > > > SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the > > > driver resume_noirq() callback. > > > > > > Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar") > > > > I'm fine with the fix itself, but since e015f88c368d appeared more > > than two years ago in v4.5, the justification for merging this after > > the merge window is a little weak. > > V1 of this fix was posted in November 2017, but IIRC, the series became > the target of some bike-shedding... > > > Is there a more recent change that exposed this problem? The usual > > situation is that we merged something during the v5.1 merge window > > that caused a regression, and we're now fixing that before v5.1 final. > > There are several reasons most people couldn't even run suspend/resume > cycles on their systems: > 1. Early releases of the affected boards came with firmware revisions with > non-functional PSCI system suspend, > 2. Preparing the PMIC for suspend required ugly assistance from i2cset > in userspace, until the Linux driver learned to take care of that itself > in v4.18/v4.19. > > I guess the fix can survive postponing to v5.2, though... Ok, I'll merge it to -next for v5.2, thanks. Bjorn
On 3/28/19 7:59 PM, Bjorn Helgaas wrote: > On Thu, Mar 28, 2019 at 03:59:11PM +0100, Geert Uytterhoeven wrote: >> On Thu, Mar 28, 2019 at 3:18 PM Bjorn Helgaas <helgaas@kernel.org> wrote: >>> On Mon, Mar 25, 2019 at 08:43:19PM +0100, marek.vasut@gmail.com wrote: >>>> From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com> >>>> >>>> Reestablish the PCIe link very early in the resume process in case it >>>> went down to prevent PCI accesses from hanging the bus. Such accesses >>>> can happen early in the PCI resume process, as early as the >>>> SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the >>>> driver resume_noirq() callback. >>>> >>>> Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar") >>> >>> I'm fine with the fix itself, but since e015f88c368d appeared more >>> than two years ago in v4.5, the justification for merging this after >>> the merge window is a little weak. >> >> V1 of this fix was posted in November 2017, but IIRC, the series became >> the target of some bike-shedding... >> >>> Is there a more recent change that exposed this problem? The usual >>> situation is that we merged something during the v5.1 merge window >>> that caused a regression, and we're now fixing that before v5.1 final. >> >> There are several reasons most people couldn't even run suspend/resume >> cycles on their systems: >> 1. Early releases of the affected boards came with firmware revisions with >> non-functional PSCI system suspend, >> 2. Preparing the PMIC for suspend required ugly assistance from i2cset >> in userspace, until the Linux driver learned to take care of that itself >> in v4.18/v4.19. >> >> I guess the fix can survive postponing to v5.2, though... > > Ok, I'll merge it to -next for v5.2, thanks. ACK.
diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c index c8febb009454..6a4e435bd35f 100644 --- a/drivers/pci/controller/pcie-rcar.c +++ b/drivers/pci/controller/pcie-rcar.c @@ -46,6 +46,7 @@ /* Transfer control */ #define PCIETCTLR 0x02000 +#define DL_DOWN BIT(3) #define CFINIT 1 #define PCIETSTR 0x02004 #define DATA_LINK_ACTIVE 1 @@ -94,6 +95,7 @@ #define MACCTLR 0x011058 #define SPEED_CHANGE BIT(24) #define SCRAMBLE_DISABLE BIT(27) +#define PMSR 0x01105c #define MACS2R 0x011078 #define MACCGSPSETR 0x011084 #define SPCNGRSN BIT(31) @@ -1130,6 +1132,7 @@ static int rcar_pcie_probe(struct platform_device *pdev) pcie = pci_host_bridge_priv(bridge); pcie->dev = dev; + platform_set_drvdata(pdev, pcie); err = pci_parse_request_of_pci_ranges(dev, &pcie->resources, NULL); if (err) @@ -1221,10 +1224,28 @@ static int rcar_pcie_probe(struct platform_device *pdev) return err; } +static int rcar_pcie_resume_noirq(struct device *dev) +{ + struct rcar_pcie *pcie = dev_get_drvdata(dev); + + if (rcar_pci_read_reg(pcie, PMSR) && + !(rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN)) + return 0; + + /* Re-establish the PCIe link */ + rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR); + return rcar_pcie_wait_for_dl(pcie); +} + +static const struct dev_pm_ops rcar_pcie_pm_ops = { + .resume_noirq = rcar_pcie_resume_noirq, +}; + static struct platform_driver rcar_pcie_driver = { .driver = { .name = "rcar-pcie", .of_match_table = rcar_pcie_of_match, + .pm = &rcar_pcie_pm_ops, .suppress_bind_attrs = true, }, .probe = rcar_pcie_probe,