bd2767ec3d
Fix the below warning by avoding calls to tmc_etr_enable_hw, if we are reusing the ETR buffer for multiple sources in sysfs mode. echo 1 > /sys/bus/coresight/devices/tmc_etr0/enable_sink echo 1 > /sys/bus/coresight/devices/ete1/enable_source echo 1 > /sys/bus/coresight/devices/ete2/enable_source [ 166.918290] ------------[ cut here ]------------ [ 166.922905] WARNING: CPU: 4 PID: 2288 at drivers/hwtracing/coresight/coresight-tmc-etr.c:1037 tmc_etr_enable_hw+0xb0/0xc8 [ 166.933862] Modules linked in: [ 166.936911] CPU: 4 PID: 2288 Comm: bash Not tainted 6.5.0-rc7 #132 [ 166.943084] Hardware name: Marvell CN106XX board (DT) [ 166.948127] pstate: 834000c9 (Nzcv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) [ 166.955083] pc : tmc_etr_enable_hw+0xb0/0xc8 [ 166.959345] lr : tmc_enable_etr_sink+0x134/0x210 snip.. 167.038545] Call trace: [ 167.040982] tmc_etr_enable_hw+0xb0/0xc8 [ 167.044897] tmc_enable_etr_sink+0x134/0x210 [ 167.049160] coresight_enable_path+0x160/0x278 [ 167.053596] coresight_enable+0xd4/0x298 [ 167.057510] enable_source_store+0x54/0xa0 [ 167.061598] dev_attr_store+0x20/0x40 [ 167.065254] sysfs_kf_write+0x4c/0x68 [ 167.068909] kernfs_fop_write_iter+0x128/0x200 [ 167.073345] vfs_write+0x1ac/0x2f8 [ 167.076739] ksys_write+0x74/0x110 [ 167.080132] __arm64_sys_write+0x24/0x38 [ 167.084045] invoke_syscall.constprop.0+0x58/0xf8 [ 167.088744] do_el0_svc+0x60/0x160 [ 167.092137] el0_svc+0x40/0x170 [ 167.095273] el0t_64_sync_handler+0x100/0x130 [ 167.099621] el0t_64_sync+0x190/0x198 [ 167.103277] ---[ end trace 0000000000000000 ]--- -bash: echo: write error: Device or resource busy Fixes: 296b01fd106e ("coresight: Refactor out buffer allocation function for ETR") Signed-off-by: Linu Cherian <lcherian@marvell.com> Reviewed-by: James Clark <james.clark@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20230823042948.12879-1-lcherian@marvell.com
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.