Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On 04/29/2016 11:37 AM, Richard W.M. Jones wrote: On Fri, Apr 29, 2016 at 08:16:35AM -0700, Greg KH wrote: On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On 04/29/2016 11:37 AM, Richard W.M. Jones wrote: On Fri, Apr 29, 2016 at 08:16:35AM -0700, Greg KH wrote: On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 05:02:57PM +0100, Richard W.M. Jones wrote: > On Fri, Apr 29, 2016 at 08:54:13AM -0700, Greg KH wrote: > > You are trying to take a generalized kernel and somehow "know" about the > > hardware ahead of time it is going to run on. That seems like two > > conflicting

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 05:02:57PM +0100, Richard W.M. Jones wrote: > On Fri, Apr 29, 2016 at 08:54:13AM -0700, Greg KH wrote: > > You are trying to take a generalized kernel and somehow "know" about the > > hardware ahead of time it is going to run on. That seems like two > > conflicting

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 08:54:13AM -0700, Greg KH wrote: > You are trying to take a generalized kernel and somehow "know" about the > hardware ahead of time it is going to run on. That seems like two > conflicting requirements, don't you agree? We would have the 8250 serial port in any kernel.

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 08:54:13AM -0700, Greg KH wrote: > You are trying to take a generalized kernel and somehow "know" about the > hardware ahead of time it is going to run on. That seems like two > conflicting requirements, don't you agree? We would have the 8250 serial port in any kernel.

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 04:37:57PM +0100, Richard W.M. Jones wrote: > On Fri, Apr 29, 2016 at 08:16:35AM -0700, Greg KH wrote: > > On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: > > > On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > > > > On Thu, Apr 28, 2016 at

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 04:37:57PM +0100, Richard W.M. Jones wrote: > On Fri, Apr 29, 2016 at 08:16:35AM -0700, Greg KH wrote: > > On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: > > > On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > > > > On Thu, Apr 28, 2016 at

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 08:16:35AM -0700, Greg KH wrote: > On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: > > On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > > > On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > > > > Currently autoconf spends

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 08:16:35AM -0700, Greg KH wrote: > On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: > > On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > > > On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > > > > Currently autoconf spends

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: > On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > > On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > > > Currently autoconf spends 25ms (on my laptop) testing if the UART > > > exported to it by KVM

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 09:10:06AM +0100, Richard W.M. Jones wrote: > On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > > On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > > > Currently autoconf spends 25ms (on my laptop) testing if the UART > > > exported to it by KVM

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 08:41:14AM +0100, Richard W.M. Jones wrote: > On Fri, Apr 29, 2016 at 10:01:08AM +0300, Matwey V. Kornilov wrote: > > 2016-04-29 1:18 GMT+03:00 Richard W.M. Jones : > > > [This is an opinionated patch, mainly for discussion.] > > > > > > I'm trying to

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 08:41:14AM +0100, Richard W.M. Jones wrote: > On Fri, Apr 29, 2016 at 10:01:08AM +0300, Matwey V. Kornilov wrote: > > 2016-04-29 1:18 GMT+03:00 Richard W.M. Jones : > > > [This is an opinionated patch, mainly for discussion.] > > > > > > I'm trying to reduce the time taken

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > > Currently autoconf spends 25ms (on my laptop) testing if the UART > > exported to it by KVM is an 8250 without FIFO and/or with strange > > quirks, which it obviously

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Thu, Apr 28, 2016 at 03:56:33PM -0700, Greg KH wrote: > On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > > Currently autoconf spends 25ms (on my laptop) testing if the UART > > exported to it by KVM is an 8250 without FIFO and/or with strange > > quirks, which it obviously

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 10:01:08AM +0300, Matwey V. Kornilov wrote: > 2016-04-29 1:18 GMT+03:00 Richard W.M. Jones : > > [This is an opinionated patch, mainly for discussion.] > > > > I'm trying to reduce the time taken in the kernel in initcalls, with > > my aim being to reduce

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Fri, Apr 29, 2016 at 10:01:08AM +0300, Matwey V. Kornilov wrote: > 2016-04-29 1:18 GMT+03:00 Richard W.M. Jones : > > [This is an opinionated patch, mainly for discussion.] > > > > I'm trying to reduce the time taken in the kernel in initcalls, with > > my aim being to reduce the current ~700ms

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

2016-04-29 1:18 GMT+03:00 Richard W.M. Jones : > [This is an opinionated patch, mainly for discussion.] > > I'm trying to reduce the time taken in the kernel in initcalls, with > my aim being to reduce the current ~700ms spent in initcalls before > userspace, down to something

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

2016-04-29 1:18 GMT+03:00 Richard W.M. Jones : > [This is an opinionated patch, mainly for discussion.] > > I'm trying to reduce the time taken in the kernel in initcalls, with > my aim being to reduce the current ~700ms spent in initcalls before > userspace, down to something like 100ms. All

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On 04/28/2016 03:18 PM, Richard W.M. Jones wrote: > [This is an opinionated patch, mainly for discussion.] > > I'm trying to reduce the time taken in the kernel in initcalls, with > my aim being to reduce the current ~700ms spent in initcalls before > userspace, down to something like 100ms. All

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On 04/28/2016 03:18 PM, Richard W.M. Jones wrote: > [This is an opinionated patch, mainly for discussion.] > > I'm trying to reduce the time taken in the kernel in initcalls, with > my aim being to reduce the current ~700ms spent in initcalls before > userspace, down to something like 100ms. All

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > Currently autoconf spends 25ms (on my laptop) testing if the UART > exported to it by KVM is an 8250 without FIFO and/or with strange > quirks, which it obviously isn't. Assume it is exported to us by a > hypervisor, it's a

Re: [PATCH] 8250: Hypervisors always export working 16550A UARTs.

On Thu, Apr 28, 2016 at 11:18:33PM +0100, Richard W.M. Jones wrote: > Currently autoconf spends 25ms (on my laptop) testing if the UART > exported to it by KVM is an 8250 without FIFO and/or with strange > quirks, which it obviously isn't. Assume it is exported to us by a > hypervisor, it's a

[PATCH] 8250: Hypervisors always export working 16550A UARTs.

[This is an opinionated patch, mainly for discussion.] I'm trying to reduce the time taken in the kernel in initcalls, with my aim being to reduce the current ~700ms spent in initcalls before userspace, down to something like 100ms. All times on my Broadwell-U laptop, under virtualization. The

[PATCH] 8250: Hypervisors always export working 16550A UARTs.

[This is an opinionated patch, mainly for discussion.] I'm trying to reduce the time taken in the kernel in initcalls, with my aim being to reduce the current ~700ms spent in initcalls before userspace, down to something like 100ms. All times on my Broadwell-U laptop, under virtualization. The

[PATCH] 8250: Hypervisors always export working 16550A UARTs.

Currently autoconf spends 25ms (on my laptop) testing if the UART exported to it by KVM is an 8250 without FIFO and/or with strange quirks, which it obviously isn't. Assume it is exported to us by a hypervisor, it's a normal, working 16550A. Signed-off-by: Richard W.M. Jones

[PATCH] 8250: Hypervisors always export working 16550A UARTs.

Currently autoconf spends 25ms (on my laptop) testing if the UART exported to it by KVM is an 8250 without FIFO and/or with strange quirks, which it obviously isn't. Assume it is exported to us by a hypervisor, it's a normal, working 16550A. Signed-off-by: Richard W.M. Jones ---