On Monday 30 October 2017 07:37 PM, Faiz Abbas wrote: > Hi, > > The variable *initialized* in mmc_initialize() is declared as static and > initialised to 0 in the following commit. This makes the compiler put it > in the .bss section of the image. > > commit 1b26bab12e85e8b0d382d6775e40d14445249574 > Author: Daniel Kochmański <[email protected]> > Date: Fri May 29 16:55:43 2015 +0200 > > mmc: Protect `mmc_initialize` from initialising mmc multiple times > > `mmc_initialize` might be called multiple times leading to the > mmc-controllers being initialised twice, and initialising the > `mmc_devices` list head twice which may lead to memory leaks. > > Signed-off-by: Daniel Kochmański <[email protected]> > CC: Roy Spliet <[email protected]> > Cc: Ian Campbell <[email protected]> > CC: Pantelis Antoniou <[email protected]> > Acked-by: Hans de Goede <[email protected]> > Signed-off-by: Hans de Goede <[email protected]> > > diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c > index da47037..f12546a 100644 > --- a/drivers/mmc/mmc.c > +++ b/drivers/mmc/mmc.c > @@ -1762,6 +1762,11 @@ static void do_preinit(void) > > int mmc_initialize(bd_t *bis) > { > + static int initialized = 0; > + if (initialized) /* Avoid initializing mmc multiple times */ > + return 0; > + initialized = 1; > + > INIT_LIST_HEAD (&mmc_devices); > cur_dev_num = 0; > > > .bss should not be accessed in u-boot before relocation because it > overlaps with fdt and writing to variables in .bss can corrupt the fdt. > MMC can be probed before relocation if it contains the u-boot > environment. Therefore, I tried to move this variable to the .data > section by > > static int initialized __attribute__((section(".data"))); > > When *initialized* was a part of .bss it was getting re-initilized to 0 > as a part of relocation. Therefore, mmc was getting probed again > successfully after relocation with new addresses for mmc devices. > > Now when *initialized* is not a part of .bss, it holds its value across > relocation and a second call to mmc_initialize() returns without doing > anything. However, the *mmc_devices* list containing pointers to the > older locations of mmc devices is not refreshed and thus mmc devices > fail to enumerate. > > So *initialized* is a problem whether it is in .data or .bss. > I am not sure how to fix this. Any help is appreciated.
I have been told that all pointers are supposed to be updated during relocation. Can anyone point to relevant code or example of the same? Thanks, Faiz _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
