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[ Upstream commit0fef6bb730] In MCQ mode, when a device command uses a hardware queue shared with other commands, a race condition may occur in the following scenario: 1. A device command is completed in CQx with CQE entry "e". 2. The interrupt handler copies the "cqe" pointer to "hba->dev_cmd.cqe" and completes "hba->dev_cmd.complete". 3. The "ufshcd_wait_for_dev_cmd()" function is awakened and retrieves the OCS value from "hba->dev_cmd.cqe". However, there is a possibility that the CQE entry "e" will be overwritten by newly completed commands in CQx, resulting in an incorrect OCS value being received by "ufshcd_wait_for_dev_cmd()". To avoid this race condition, the OCS value should be immediately copied to the struct "lrb" of the device command. Then "ufshcd_wait_for_dev_cmd()" can retrieve the OCS value from the struct "lrb". Fixes:57b1c0ef89("scsi: ufs: core: mcq: Add support to allocate multiple queues") Suggested-by: Can Guo <quic_cang@quicinc.com> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> Link: https://lore.kernel.org/r/20230610021553.1213-2-powen.kao@mediatek.com Tested-by: Po-Wen Kao <powen.kao@mediatek.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
1414 lines
45 KiB
1414 lines
45 KiB