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    SubjectRe: [PATCH v2 2/3] fpga manager: framework core
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    Hi Pavel,

    > On Oct 24, 2014, at 1:52 PM, Pavel Machek <pavel@denx.de> wrote:
    >
    > Hi!
    >
    >> * /sys/class/fpga_manager/<fpga>/firmware
    >> Name of FPGA image file to load using firmware class.
    >> $ echo image.rbf > /sys/class/fpga_manager/<fpga>/firmware
    >
    > I .. still don't think this is good idea. What about namespaces?
    > The path corresponds to path in which namespace?
    >

    FWIW the overlays patchset uses binary configfs attribute to make this work.

    >> +int fpga_mgr_write(struct fpga_manager *mgr, const char *buf, size_t count)
    >> +{
    >> + int ret;
    >> +
    >> + if (test_and_set_bit_lock(FPGA_MGR_BUSY, &mgr->flags))
    >> + return -EBUSY;
    >> +
    >> + dev_info(mgr->dev, "writing buffer to %s\n", mgr->name);
    >> +
    >> + ret = __fpga_mgr_write(mgr, buf, count);
    >> + clear_bit_unlock(FPGA_MGR_BUSY, &mgr->flags);
    >> +
    >> + return ret;
    >> +}
    >> +EXPORT_SYMBOL_GPL(fpga_mgr_write);
    >
    > Is the EBUSY -- userspace please try again, but you don't know when to
    > try again -- right interface? I mean, normally kernel would wait, so
    > that userland does not have to poll?
    >
    >> +static ssize_t fpga_mgr_firmware_store(struct device *dev,
    >> + struct device_attribute *attr,
    >> + const char *buf, size_t count)
    >> +{
    >> + struct fpga_manager *mgr = dev_get_drvdata(dev);
    >> + unsigned int len;
    >> + char image_name[NAME_MAX];
    >> + int ret;
    >> +
    >> + /* lose terminating \n */
    >> + strcpy(image_name, buf);
    >> + len = strlen(image_name);
    >> + if (image_name[len - 1] == '\n')
    >> + image_name[len - 1] = 0;
    >> +
    >> + ret = fpga_mgr_firmware_write(mgr, image_name);
    >> + if (ret)
    >> + return ret;
    >> +
    >> + return count;
    >> +}
    >
    > This shows why the interface is not right... Valid filename may
    > contain \n, right? It may even end with \n.
    >

    I could argue that a valid firmware file is one that’s well formed and does not
    contain those characters.

    I guess this is only for make echo file >foo work. You could specify that echo -n file >foo is
    required.


    > Best regards,
    > Pavel
    > --
    > (english) http://www.livejournal.com/~pavelmachek
    > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

    Regards

    — Pantelis

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