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[ Upstream commit 6d303e4b19d694cdbebf76bcdb51ada664ee953d ] During clock gating (ufshcd_gate_work()), we first put the link hibern8 by calling ufshcd_uic_hibern8_enter() and if ufshcd_uic_hibern8_enter() returns success (0) then we gate all the clocks. Now let’s zoom in to what ufshcd_uic_hibern8_enter() does internally: It calls __ufshcd_uic_hibern8_enter() and if failure is encountered, link recovery shall put the link back to the highest HS gear and returns success (0) to ufshcd_uic_hibern8_enter() which is the issue as link is still in active state due to recovery! Now ufshcd_uic_hibern8_enter() returns success to ufshcd_gate_work() and hence it goes ahead with gating the UFS clock while link is still in active state hence I believe controller would raise UIC error interrupts. But when we service the interrupt, clocks might have already been disabled! This change fixes for this by returning failure from __ufshcd_uic_hibern8_enter() if recovery succeeds as link is still not in hibern8, upon receiving the error ufshcd_hibern8_enter() would initiate retry to put the link state back into hibern8. Link: https://lore.kernel.org/r/1573798172-20534-8-git-send-email-cang@codeaurora.org Reviewed-by: Avri Altman <avri.altman@wdc.com> Reviewed-by: Bean Huo <beanhuo@micron.com> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> Signed-off-by: Can Guo <cang@codeaurora.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.