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 linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 20 Feb 2017 11:40:35 +0900 From: Tomasz Figa <tfiga@...omium.org> To: zain wang <wzz@...k-chips.com> Cc: Sean Paul <seanpaul@...omium.org>, Daniel Vetter <daniel.vetter@...ll.ch>, Inki Dae <inki.dae@...sung.com>, David Airlie <airlied@...ux.ie>, Tomeu Vizoso <tomeu.vizoso@...labora.com>, Mika Kahola <mika.kahola@...el.com>, Stéphane Marchesin <marcheu@...omium.org>, Douglas Anderson <dianders@...omium.org>, Thierry Reding <treding@...dia.com>, Heiko Stuebner <heiko@...ech.de>, Jingoo Han <jingoohan1@...il.com>, Javier Martinez Canillas <javier@....samsung.com>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, dri-devel <dri-devel@...ts.freedesktop.org>, linux-samsung-soc <linux-samsung-soc@...r.kernel.org>, "open list:ARM/Rockchip SoC..." <linux-rockchip@...ts.infradead.org> Subject: Re: [PATCH] drm/bridge: analogix_dp: Don't return -EBUSY when msg->size is 0 in aux transaction Hi Zain, On Mon, Feb 13, 2017 at 6:27 PM, zain wang <wzz@...k-chips.com> wrote: > > The analogix_dp_transfer() will return -EBUSY if num_transferred is zero. > But sometimes we will send a bare address packet to start the transaction, > like drm_dp_i2c_xfer() show: > ...... > /* Send a bare address packet to start the transaction. > * Zero sized messages specify an address only (bare > * address) transaction. > */ > msg.buffer = NULL; > msg.size = 0; > err = drm_dp_i2c_do_msg(aux, &msg); > ...... > > In this case, the msg->size is zero, so the num_transferred will be zero too. > We can't return -EBUSY here, let's we return num_transferred if num_transferred > equals msg->size. > Please see my question inline. > Signed-off-by: zain wang <wzz@...k-chips.com> > --- > drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c > index 303083a..5384aca 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c > @@ -1162,5 +1162,5 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp, > (msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_READ) > msg->reply = DP_AUX_NATIVE_REPLY_ACK; > > - return num_transferred > 0 ? num_transferred : -EBUSY; > + return (num_transferred == msg->size) ? num_transferred : -EBUSY; I might be missing something but, looking at the code, I don't see any possibility of num_transferred ever being different than msg->size. To be honest, it doesn't seem to even make any sense keeping the local variable there, because msg->size can be simply always returned, as errors are handled by jumping to aux_error label. Best regards, Tomasz
Powered by blists - more mailing lists