Hi there, I'm experiencing system lockups with 2.6.24 which I believe to be related to scsi error handling. Actually, I have patched the mainline kernel with a disk shock protection patch [1] and in my case it is indeed the shock protection mechanism that triggers the lockups. However, some rather lengthy investigations have lead me to the conclusion that this additional patch is just the means to reproduce the error condition fairly reliably rather than the origin of the problem. The problem has only become apparent since Tejun's commit 31cc23b34913bc173680bdc87af79e551bf8cc0d. More precisely, libata now sets max_host_blocked and max_device_blocked to 1 for all ATA devices. Various tests I've conducted so far have lead me to the conclusion that a non zero return code from scsi_dispatch_command is sufficient to trigger the problem I'm seeing provided that max_host_blocked and max_device_blocked are set to 1. Unfortunately, I'm a bit at a loss as to how I should proceed to find the culprit. I can reliably reproduce the problem using the disk shock protection patch in order to cause non zero return values from scsi_dispatch_command. How can I find out where in the error handling of this condition things might go wrong? Most likely you will need further information to help me solving this issue but perhaps you can already come up with some suggestions and tell me what else you'd like to know. Thanks in advance, Elias [1] http://article.gmane.org/gmane.linux.drivers.hdaps.devel/1094 PS: Since the disk shock protection patch is mainly concerned with an ATA specific feature, I'm currently working on it to implement it in libata rather than in the scsi midlayer. This doesn't change anything with regard to the problem I've described above but has confirmed my suspicion that it must be the return code from scsi_dispatch_command that triggers system freeze. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
