Messages in this thread | | | From | Noam Camus <> | Subject | RE: [PATCH 3/4] serial: 8250_dw: Add UPF_FIXED_TYPE to flags | Date | Thu, 23 Jul 2015 10:38:11 +0000 |
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From: Peter Hurley [mailto:peter@hurleysoftware.com] Sent: Wednesday, July 22, 2015 3:39 PM
>> + /* Writing to LCR may cause BUSY interrupt before we >> + * register the IRQ line. >> + * Currently autoconf() uses several writes to LCR. >> + * In order to avoid calling to autoconf() always add >> + * following flag. >> + */ >> + p->flags |= UPF_FIXED_TYPE; > > Why only for devicetree DW8250's? Don't all DW8250's have this LCR "feature"? > Yes, all DW8250 got this "feature" i.e. busy functionality.
> And what port type does this id DW8250's as, PORT_8250? Except with fifos, autoflow control, dma, etc.? The only thing that DW8250 is not fully 16550 compatibility is this busy functionality feature. This feature means that a serial transfer is in progress. It is indicated by special identification in IIR, and raised when LCR is written while device is busy.
> If the port type is being fixed, then please fix it to a new port type. As an extension to 16550 type is not fixed.
Seem that I need to rethink on this. I will remove this commit from v2 patch set till I will be sure what is the right thing to do.
Noam
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