| Message ID | 1362126969-32277-1-git-send-email-heikki.krogerus@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/01/2013 09:36 AM, Heikki Krogerus wrote: > Setting the reg-io-width to 1 byte represents more accurate > description of the HW. > > This will fix an issue where UART driver causes kernel > panic during bootup. Gregory CLEMENT traced the issue to > autoconfig() in 8250.c, where the existence of FIFO is > checked from UART_IIR register. The register is now read as > 32-bit value as the reg-io-width is set to 4-bytes. The > retuned value seems to contain bogus data for bits 31:8, > causing the issue. I have tested this patch on the Armada XP based board DB-MV784MP-GP, and it fixed the issue. I had few doubts on the fact it worked, but with this test you can add my: Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> and also my Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com> as co-maintainer of the mvebu subsystem. Thanks for your patch. > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > Cc: Gregory CLEMENT <gregory.clement@free-electrons.com> > Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> > --- > arch/arm/boot/dts/armada-370-xp.dtsi | 4 ++-- > arch/arm/boot/dts/armada-xp.dtsi | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi > index 6f1acc7..99afca4 100644 > --- a/arch/arm/boot/dts/armada-370-xp.dtsi > +++ b/arch/arm/boot/dts/armada-370-xp.dtsi > @@ -54,7 +54,7 @@ > reg = <0xd0012000 0x100>; > reg-shift = <2>; > interrupts = <41>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > serial@d0012100 { > @@ -62,7 +62,7 @@ > reg = <0xd0012100 0x100>; > reg-shift = <2>; > interrupts = <42>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > > diff --git a/arch/arm/boot/dts/armada-xp.dtsi b/arch/arm/boot/dts/armada-xp.dtsi > index 1443949..ca00d83 100644 > --- a/arch/arm/boot/dts/armada-xp.dtsi > +++ b/arch/arm/boot/dts/armada-xp.dtsi > @@ -46,7 +46,7 @@ > reg = <0xd0012200 0x100>; > reg-shift = <2>; > interrupts = <43>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > serial@d0012300 { > @@ -54,7 +54,7 @@ > reg = <0xd0012300 0x100>; > reg-shift = <2>; > interrupts = <44>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > >
(2013/03/01 17:36), Heikki Krogerus wrote: > Setting the reg-io-width to 1 byte represents more accurate > description of the HW. > > This will fix an issue where UART driver causes kernel > panic during bootup. Gregory CLEMENT traced the issue to > autoconfig() in 8250.c, where the existence of FIFO is > checked from UART_IIR register. The register is now read as > 32-bit value as the reg-io-width is set to 4-bytes. The > retuned value seems to contain bogus data for bits 31:8, > causing the issue. > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > Cc: Gregory CLEMENT <gregory.clement@free-electrons.com> > Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> I've tested this patch on Armada-XP based OpenBlocks AX3/4 and fixed the issue. Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Thank you! > --- > arch/arm/boot/dts/armada-370-xp.dtsi | 4 ++-- > arch/arm/boot/dts/armada-xp.dtsi | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi > index 6f1acc7..99afca4 100644 > --- a/arch/arm/boot/dts/armada-370-xp.dtsi > +++ b/arch/arm/boot/dts/armada-370-xp.dtsi > @@ -54,7 +54,7 @@ > reg = <0xd0012000 0x100>; > reg-shift = <2>; > interrupts = <41>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > serial@d0012100 { > @@ -62,7 +62,7 @@ > reg = <0xd0012100 0x100>; > reg-shift = <2>; > interrupts = <42>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > > diff --git a/arch/arm/boot/dts/armada-xp.dtsi b/arch/arm/boot/dts/armada-xp.dtsi > index 1443949..ca00d83 100644 > --- a/arch/arm/boot/dts/armada-xp.dtsi > +++ b/arch/arm/boot/dts/armada-xp.dtsi > @@ -46,7 +46,7 @@ > reg = <0xd0012200 0x100>; > reg-shift = <2>; > interrupts = <43>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > serial@d0012300 { > @@ -54,7 +54,7 @@ > reg = <0xd0012300 0x100>; > reg-shift = <2>; > interrupts = <44>; > - reg-io-width = <4>; > + reg-io-width = <1>; > status = "disabled"; > }; > >
diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi index 6f1acc7..99afca4 100644 --- a/arch/arm/boot/dts/armada-370-xp.dtsi +++ b/arch/arm/boot/dts/armada-370-xp.dtsi @@ -54,7 +54,7 @@ reg = <0xd0012000 0x100>; reg-shift = <2>; interrupts = <41>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; }; serial@d0012100 { @@ -62,7 +62,7 @@ reg = <0xd0012100 0x100>; reg-shift = <2>; interrupts = <42>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; }; diff --git a/arch/arm/boot/dts/armada-xp.dtsi b/arch/arm/boot/dts/armada-xp.dtsi index 1443949..ca00d83 100644 --- a/arch/arm/boot/dts/armada-xp.dtsi +++ b/arch/arm/boot/dts/armada-xp.dtsi @@ -46,7 +46,7 @@ reg = <0xd0012200 0x100>; reg-shift = <2>; interrupts = <43>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; }; serial@d0012300 { @@ -54,7 +54,7 @@ reg = <0xd0012300 0x100>; reg-shift = <2>; interrupts = <44>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; };
Setting the reg-io-width to 1 byte represents more accurate description of the HW. This will fix an issue where UART driver causes kernel panic during bootup. Gregory CLEMENT traced the issue to autoconfig() in 8250.c, where the existence of FIFO is checked from UART_IIR register. The register is now read as 32-bit value as the reg-io-width is set to 4-bytes. The retuned value seems to contain bogus data for bits 31:8, causing the issue. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: Gregory CLEMENT <gregory.clement@free-electrons.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> --- arch/arm/boot/dts/armada-370-xp.dtsi | 4 ++-- arch/arm/boot/dts/armada-xp.dtsi | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-)