mainlining shenanigans
The wmb() inside ufshcd_send_command() is added to make sure that the doorbell is committed immediately. This leads to couple of expectations: 1. The doorbell write should complete before the function return. 2. The doorbell write should not cross the function boundary. 2nd expectation is fullfilled by the Linux memory model as there is a guarantee that the critical section won't cross the unlock (release) operation. 1st expectation is not really needed here as there is no following read/ write that depends on the doorbell to be complete implicitly. Even if the doorbell write is in a CPUs Write Buffer (WB), wmb() won't flush it. And there is no real need of a WB flush here as well. So let's get rid of the wmb() that seems redundant. Link: https://lore.kernel.org/r/20220504084212.11605-5-manivannan.sadhasivam@linaro.org Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Bean Huo <beanhuo@micron.com> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. 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.