lkml.org 
[lkml]   [2019]   [May]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 3/3] soc: qcom: mdt_loader: add offset to request_firmware_into_buf
    On Thu 23 May 09:56 PDT 2019, Greg Kroah-Hartman wrote:

    > On Thu, May 23, 2019 at 09:41:49AM -0700, Scott Branden wrote:
    > > Hi Greg,
    > >
    > > On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
    > > > On Wed, May 22, 2019 at 07:51:13PM -0700, Scott Branden wrote:
    > > > > Adjust request_firmware_into_buf API to allow for portions
    > > > > of firmware file to be read into a buffer. mdt_loader still
    > > > > retricts request fo whole file read into buffer.
    > > > >
    > > > > Signed-off-by: Scott Branden <scott.branden@broadcom.com>
    > > > > ---
    > > > > drivers/soc/qcom/mdt_loader.c | 7 +++++--
    > > > > 1 file changed, 5 insertions(+), 2 deletions(-)
    > > > >
    > > > > diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
    > > > > index 1c488024c698..ad20d159699c 100644
    > > > > --- a/drivers/soc/qcom/mdt_loader.c
    > > > > +++ b/drivers/soc/qcom/mdt_loader.c
    > > > > @@ -172,8 +172,11 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
    > > > > if (phdr->p_filesz) {
    > > > > sprintf(fw_name + fw_name_len - 3, "b%02d", i);
    > > > > - ret = request_firmware_into_buf(&seg_fw, fw_name, dev,
    > > > > - ptr, phdr->p_filesz);
    > > > > + ret = request_firmware_into_buf
    > > > > + (&seg_fw, fw_name, dev,
    > > > > + ptr, phdr->p_filesz,
    > > > > + 0,
    > > > > + KERNEL_PREAD_FLAG_WHOLE);
    > > > So, all that work in the first 2 patches for no real change at all? Why
    > > > are these changes even needed?
    > >
    > > The first two patches allow partial read of files into memory.
    > >
    > > Existing kernel drivers haven't need such functionality so, yes, there
    > > should be no real change
    > >
    > > with first two patches other than adding such partial file read support.
    > >
    > > We have a new driver in development which needs partial read of files
    > > supported in the kernel.
    >
    > As I said before, I can not take new apis without any in-kernel user.
    > So let's wait for your new code that thinks it needs this, and then we
    > will be glad to evaluate all of this at that point in time.
    >

    The .mdt files are ELF files split to avoid having to allocate large
    (5-60MB) chunks of temporary firmware buffers while installing the
    segments.

    But for multiple reasons it would be nice to be able to load the
    non-split ELF files and the proposed interface would allow this.

    So I definitely like the gist of the series.

    > To do so otherwise is to have loads of unused "features" aquiring cruft
    > in the kernel source, and you do not want that.
    >

    Agreed.

    I'll take the opportunity and see if I can implement this (support for
    non-split Qualcomm firmware) based on the patches in this series.

    Regards,
    Bjorn

    \
     
     \ /
      Last update: 2019-05-27 07:38    [W:2.268 / U:0.912 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site