On Mon, Jun 15, 2020 at 12:40:19PM +0300, Andy Shevchenko wrote: > On Sun, Jun 14, 2020 at 02:02:54PM -0700, Sultan Alsawaf wrote: > > From: Sultan Alsawaf <sultan@xxxxxxxxxxxxxxx> > > > > SMBus block reads can be broken because the read function will just skip > > over bytes it doesn't like until reaching a byte that conforms to the > > length restrictions for block reads. This is problematic when it isn't > > known if the incoming payload is indeed a conforming block read. > > > > According to the SMBus specification, block reads will only send the > > payload length in the first byte, so we can fix this by only considering > > the first byte in a sequence for block read length purposes. > > I'm wondering if this overlaps with [1]. AFAIU that one is also makes sure that > the length is not a garbage. > > [1]: https://lore.kernel.org/linux-i2c/20200613104109.2989-1-mans@xxxxxxxxx/T/#u No overlap. That looks like a similar bug for a different driver. In my case, the adapter provides native SMBus support, so emulation is never used. This is clear to see by looking at i2c_transfer_buffer_flags(), which only uses the master_xfer functions provided by the adapter; it doesn't call the emulation path at all. Sultan
