On Mon, 6 Dec 2010, Retallack, Mark wrote: > Hi, > > I have found an issue with the SMC (and SCC) quicc serial driver where > if the CPM is under heavy load, the serial driver will stop > transmitting any data which can lead to the serial driver locking up > (if using buffered serial driver and blocking writes). This issue > shows up when the Serial driver is re-configured. > > This is caused by the CPM CP access code within the SMC/SCC serial > driver not checking for the Busy flag (FLG) to be clear before > continuing. This means that if the SMC is re-configured it may not be > restarted. The attached patch performs a wait while the busy flag is > active. > > I have also changed the sequence of the SMC UART set-up so the STOP > TRANSMIT command is executed before the SMCMR[TEN] bit is cleared. > Reading the MPC850 user manual suggests that this is the "more > correct" way of performing a re-configuration of the SMC, it would be > useful to get other peoples feedback on this change, I am not sure it > will make a difference.
Hi Mark, I looked on the patch and tested build process. The patch looks fine *for me*, but, as I have not the same targets, I cannot test run-time stuff. Could someone from maintainers, please, put his hands on this? Or what could be your verdict? Thank you, Sergei > Thanks in advance > Mark Retallack
