drivers/huawei-ups2000.c: call ser_close() before modbus_connect(), fix #3244. #3245
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networkupstools#3244. In drivers/huawei-ups2000.c, the serial port is opened twice. Once by ser_open() to manually perform device identification, once by modbus_connect() for communicating with the UPS after identification succeeds. However, holding two file descriptors of the same serial port is problematic on Windows, even if they're not actually used at the same time. A serial port is usually opened on Windows via CreateFileA() with dwShareMode = 0, which is done by libmodbus. According to the Win32 API documentation: > If this parameter is zero and CreateFile succeeds, the file or device > cannot be shared and cannot be opened again until the handle to the > file or device is closed. This is responsible for the following error on Windows: modbus_connect: unable to connect: No error Driver failed to start (exit status=1) This commit leaves only the raw ser_open() call in upsdrv_initups(), the modbus_connect() call is deleted to avoid opening the same serial port again. After device identification succeeds later in ups2000_device_identification() - called by upsdrv_initinfo(), the raw serial port is closed. Once at this point, modbus_connect() is called, just before upsdrv_initinfo() returns. Signed-off-by: Yifeng Li <[email protected]>
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❌ Build nut 2.8.4.3924-master failed (commit 52efbc79c3 by @biergaizi) |
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Looks reasonable, thanks for the quick reaction, and happy holidays! :) (Disregard the Appveyor and OBS faults for that commit, those CI services timed out the free allowance) |
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CentOS_8/ppc64le failed because the VM failed to power on. AppVeyor failed because it timed out while it was trying to update the build cache.
Fortunately the build artifact has already been uploaded before it failed. Both errors are safe to ignore. Let's merge it after #3244 reports back with a positive outcome. |
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Just tested on my personal machine (the same FreeBSD server originally used for development), no regression found on POSIX. Now waiting for end-user Windows testing... |
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I think this Pull Request can be merged now, as it's reported that the serial port function is now fixed on Windows. NUT is still not functional due to other problems (awaiting for information), but we can troubleshoot those problems later. |
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Great, thanks a lot for "knowing where to kick"! ;) |
3 participants
In
drivers/huawei-ups2000.c, the serial port is opened twice. Once byser_open()to manually perform device identification, once bymodbus_connect()for communicating with the UPS after identification succeeds.However, holding two file descriptors of the same serial port is problematic on Windows, even if they're not actually used at the same time. A serial port is usually opened on Windows via
CreateFileA()withdwShareMode = 0, which is done by libmodbus. According to the Win32 API documentation:This is responsible for the following error on Windows:
This commit leaves only the raw
ser_open()call inupsdrv_initups(), themodbus_connect()call is deleted to avoid opening the same serial port again. After device identification succeeds later inups2000_device_identification()- called byupsdrv_initinfo(), the raw serial port is closed. Once at this point,modbus_connect()is called, just beforeupsdrv_initinfo()returns.