Messages in this thread | | | From | Gustavo Pimentel <> | Subject | RE: [PATCH v5 1/6] misc: Add Synopsys DesignWare xData IP driver | Date | Thu, 11 Feb 2021 09:50:33 +0000 |
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On Thu, Feb 11, 2021 at 9:30:16, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> On Thu, Feb 11, 2021 at 10:08:38AM +0100, Gustavo Pimentel wrote: > > +static ssize_t write_show(struct device *dev, struct device_attribute *attr, > > + char *buf) > > +{ > > + struct pci_dev *pdev = to_pci_dev(dev); > > + struct dw_xdata *dw = pci_get_drvdata(pdev); > > + u64 rate; > > + > > + mutex_lock(&dw->mutex); > > + dw_xdata_perf(dw, &rate, true); > > + mutex_unlock(&dw->mutex); > > + > > + return sysfs_emit(buf, "%llu MB/s\n", rate); > > Do not put units in a sysfs file, that should be in the documentation, > otherwise this forces userspace to "parse" the units which is a mess.
Okay.
> > Same for the other sysfs file. > > And why do you need a lock for this show function?
Maybe I understood it wrongly, please correct me in that case. The dw_xdata_perf() is called on the write_show() and read_show(), to avoid a possible race condition between those calls, I have added this mutex. Thanks.
-Gustavo
> > thanks, > > greg k-h
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