lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 23 Sep 2021 22:22:31 +0200 From: Pali Rohár <pali@...nel.org> To: Andy Shevchenko <andy.shevchenko@...il.com> Cc: Jonas Dreßler <verdre@...d.nl>, Brian Norris <briannorris@...omium.org>, Amitkumar Karwar <amitkarwar@...il.com>, Ganapathi Bhat <ganapathi017@...il.com>, Xinming Hu <huxinming820@...il.com>, Kalle Valo <kvalo@...eaurora.org>, "David S. Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, Tsuchiya Yuto <kitakar@...il.com>, linux-wireless <linux-wireless@...r.kernel.org>, netdev@...r.kernel.org, Linux Kernel <linux-kernel@...r.kernel.org>, linux-pci <linux-pci@...r.kernel.org>, Maximilian Luz <luzmaximilian@...il.com>, Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, Bjorn Helgaas <bhelgaas@...gle.com> Subject: Re: [PATCH 1/2] mwifiex: Use non-posted PCI register writes On Thursday 23 September 2021 22:41:30 Andy Shevchenko wrote: > On Thu, Sep 23, 2021 at 6:28 PM Jonas Dreßler <verdre@...d.nl> wrote: > > On 9/22/21 2:50 PM, Jonas Dreßler wrote: > > ... > > > - Just calling mwifiex_write_reg() once and then blocking until the card > > wakes up using my delay-loop doesn't fix the issue, it's actually > > writing multiple times that fixes the issue > > > > These observations sound a lot like writes (and even reads) are actually > > being dropped, don't they? > > It sounds like you're writing into a not ready (fully powered on) device. This reminds me a discussion with Bjorn about CRS response returned after firmware crash / reset when device is not ready yet: https://lore.kernel.org/linux-pci/20210922164803.GA203171@bhelgaas/ Could not be this similar issue? You could check it via reading PCI_VENDOR_ID register from config space. And if it is not valid value then card is not really ready yet. > To check this, try to put a busy loop for reading and check the value > till it gets 0. > > Something like > > unsigned int count = 1000; > > do { > if (mwifiex_read_reg(...) == 0) > break; > } while (--count); > > > -- > With Best Regards, > Andy Shevchenko
Powered by blists - more mailing lists