Sercom: partially revert error handling change

[kaysievers]

Revert a part of ccfc7db. It breaks I2C communcation.

#376

[Copilot]

Pull request overview

This PR partially reverts a previous commit (ccfc7db) that broke I2C communication by changing error handling in the sendDataMasterWIRE function. The change reverts from checking the general INTFLAG.bit.ERROR flag back to checking only the specific STATUS.bit.BUSERR flag.

Key Changes:

• Reverted error detection in sendDataMasterWIRE from INTFLAG.bit.ERROR to STATUS.bit.BUSERR to fix I2C communication issues reported in issue #376

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[Copilot]

This change creates an inconsistency in error handling. Other similar I2C wait loops in this file check INTFLAG.bit.ERROR (lines 565, 578, 716), which according to the comment on line 563-564 includes all data transfer errors "rolled up from STATUS.reg".

Checking only STATUS.bit.BUSERR here may miss other error conditions like arbitration loss (ARBLOST), bus errors, etc. While this may fix the immediate I2C communication issue mentioned in #376, consider whether:

1. The same change should be applied to the other similar wait loops for consistency
2. Or if there's a different underlying issue that should be addressed

The comment on lines 606-607 also says "data transfer error" (plural) but only one error type is now being checked.

Suggested change

	if (sercom->I2CM.STATUS.bit.BUSERR) {
	if (sercom->I2CM.INTFLAG.bit.ERROR) {

[Copilot]

The comment says "If a data transfer error occurs" (suggesting multiple error types), but the code now only checks for BUSERR. Consider updating the comment to be more specific, e.g., "If a bus error occurs" or explain why only BUSERR is checked here while other similar functions check all errors via INTFLAG.bit.ERROR.

[hathach]

since we don't receive feedback by author of #367. Maybe we can do sercom->I2CM.INTFLAG.bit.ERROR || sercom->I2CM.STATUS.bit.BUSERR though I think reverting is safer choice here. Thank you for your patient.